Convert nix.conf manpage

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diff --git a/doc/manual/src/SUMMARY.md b/doc/manual/src/SUMMARY.md
index f9ef1b060..e8baf489b 100644
--- a/doc/manual/src/SUMMARY.md
+++ b/doc/manual/src/SUMMARY.md
@@ -49,6 +49,8 @@
   - [Common Environment Variables](command-ref/env-common.md)
   - [Utilities](command-ref/utilities.md)
     - [nix-copy-closure](command-ref/nix-copy-closure.md)
+  - [Files](command-ref/files.md)
+    - [nix.conf](command-ref/conf-file.md)
 - [Glossary](glossary.md)
 - [Hacking](hacking.md)
 - [Release Notes](release-notes/release-notes.md)
diff --git a/doc/manual/src/command-ref/conf-file.md b/doc/manual/src/command-ref/conf-file.md
new file mode 100644
index 000000000..3f84373e2
--- /dev/null
+++ b/doc/manual/src/command-ref/conf-file.md
@@ -0,0 +1,727 @@
+nix.conf
+
+5
+
+Nix
+
+nix.conf
+
+Nix configuration file
+
+# Description
+
+By default Nix reads settings from the following places:
+
+  - The system-wide configuration file `sysconfdir/nix/nix.conf` (i.e.
+    `/etc/nix/nix.conf` on most systems), or `$NIX_CONF_DIR/nix.conf` if
+    `NIX_CONF_DIR` is set. Values loaded in this file are not forwarded
+    to the Nix daemon. The client assumes that the daemon has already
+    loaded them.
+
+  - If `NIX_USER_CONF_FILES` is set, then each path separated by `:`
+    will be loaded in reverse order.
+    
+    Otherwise it will look for `nix/nix.conf` files in `XDG_CONFIG_DIRS`
+    and `XDG_CONFIG_HOME`. If these are unset, it will look in
+    `$HOME/.config/nix.conf`.
+
+The configuration files consist of `name =
+value` pairs, one per line. Other files can be included with a line like
+`include
+path`, where path is interpreted relative to the current conf file and a
+missing file is an error unless `!include` is used instead. Comments
+start with a `#` character. Here is an example configuration file:
+
+    keep-outputs = true       # Nice for developers
+    keep-derivations = true   # Idem
+
+You can override settings on the command line using the `--option` flag,
+e.g. `--option keep-outputs
+false`.
+
+The following settings are currently available:
+
+  - `allowed-uris`  
+    A list of URI prefixes to which access is allowed in restricted
+    evaluation mode. For example, when set to
+    `https://github.com/NixOS`, builtin functions such as `fetchGit` are
+    allowed to access `https://github.com/NixOS/patchelf.git`.
+
+  - `allow-import-from-derivation`  
+    By default, Nix allows you to `import` from a derivation, allowing
+    building at evaluation time. With this option set to false, Nix will
+    throw an error when evaluating an expression that uses this feature,
+    allowing users to ensure their evaluation will not require any
+    builds to take place.
+
+  - `allow-new-privileges`  
+    (Linux-specific.) By default, builders on Linux cannot acquire new
+    privileges by calling setuid/setgid programs or programs that have
+    file capabilities. For example, programs such as `sudo` or `ping`
+    will fail. (Note that in sandbox builds, no such programs are
+    available unless you bind-mount them into the sandbox via the
+    `sandbox-paths` option.) You can allow the use of such programs by
+    enabling this option. This is impure and usually undesirable, but
+    may be useful in certain scenarios (e.g. to spin up containers or
+    set up userspace network interfaces in tests).
+
+  - `allowed-users`  
+    A list of names of users (separated by whitespace) that are allowed
+    to connect to the Nix daemon. As with the `trusted-users` option,
+    you can specify groups by prefixing them with `@`. Also, you can
+    allow all users by specifying `*`. The default is `*`.
+    
+    Note that trusted users are always allowed to connect.
+
+  - `auto-optimise-store`  
+    If set to `true`, Nix automatically detects files in the store that
+    have identical contents, and replaces them with hard links to a
+    single copy. This saves disk space. If set to `false` (the default),
+    you can still run `nix-store
+                    --optimise` to get rid of duplicate files.
+
+  - `builders`  
+    A list of machines on which to perform builds. See
+    [???](#chap-distributed-builds) for details.
+
+  - `builders-use-substitutes`  
+    If set to `true`, Nix will instruct remote build machines to use
+    their own binary substitutes if available. In practical terms, this
+    means that remote hosts will fetch as many build dependencies as
+    possible from their own substitutes (e.g, from `cache.nixos.org`),
+    instead of waiting for this host to upload them all. This can
+    drastically reduce build times if the network connection between
+    this computer and the remote build host is slow. Defaults to
+    `false`.
+
+  - `build-users-group`  
+    This options specifies the Unix group containing the Nix build user
+    accounts. In multi-user Nix installations, builds should not be
+    performed by the Nix account since that would allow users to
+    arbitrarily modify the Nix store and database by supplying specially
+    crafted builders; and they cannot be performed by the calling user
+    since that would allow him/her to influence the build result.
+    
+    Therefore, if this option is non-empty and specifies a valid group,
+    builds will be performed under the user accounts that are a member
+    of the group specified here (as listed in `/etc/group`). Those user
+    accounts should not be used for any other purpose\!
+    
+    Nix will never run two builds under the same user account at the
+    same time. This is to prevent an obvious security hole: a malicious
+    user writing a Nix expression that modifies the build result of a
+    legitimate Nix expression being built by another user. Therefore it
+    is good to have as many Nix build user accounts as you can spare.
+    (Remember: uids are cheap.)
+    
+    The build users should have permission to create files in the Nix
+    store, but not delete them. Therefore, `/nix/store` should be owned
+    by the Nix account, its group should be the group specified here,
+    and its mode should be `1775`.
+    
+    If the build users group is empty, builds will be performed under
+    the uid of the Nix process (that is, the uid of the caller if
+    `NIX_REMOTE` is empty, the uid under which the Nix daemon runs if
+    `NIX_REMOTE` is `daemon`). Obviously, this should not be used in
+    multi-user settings with untrusted users.
+
+  - `compress-build-log`  
+    If set to `true` (the default), build logs written to
+    `/nix/var/log/nix/drvs` will be compressed on the fly using bzip2.
+    Otherwise, they will not be compressed.
+
+  - `connect-timeout`  
+    The timeout (in seconds) for establishing connections in the binary
+    cache substituter. It corresponds to `curl`’s `--connect-timeout`
+    option.
+
+  - `cores`  
+    Sets the value of the `NIX_BUILD_CORES` environment variable in the
+    invocation of builders. Builders can use this variable at their
+    discretion to control the maximum amount of parallelism. For
+    instance, in Nixpkgs, if the derivation attribute
+    `enableParallelBuilding` is set to `true`, the builder passes the
+    `-jN` flag to GNU Make. It can be overridden using the `--cores`
+    command line switch and defaults to `1`. The value `0` means that
+    the builder should use all available CPU cores in the system.
+    
+    See also [???](#chap-tuning-cores-and-jobs).
+
+  - `diff-hook`  
+    Absolute path to an executable capable of diffing build results. The
+    hook executes if [varlistentry\_title](#conf-run-diff-hook) is true,
+    and the output of a build is known to not be the same. This program
+    is not executed to determine if two results are the same.
+    
+    The diff hook is executed by the same user and group who ran the
+    build. However, the diff hook does not have write access to the
+    store path just built.
+    
+    The diff hook program receives three parameters:
+    
+    1.  A path to the previous build's results
+    
+    2.  A path to the current build's results
+    
+    3.  The path to the build's derivation
+    
+    4.  The path to the build's scratch directory. This directory will
+        exist only if the build was run with `--keep-failed`.
+    
+    The stderr and stdout output from the diff hook will not be
+    displayed to the user. Instead, it will print to the nix-daemon's
+    log.
+    
+    When using the Nix daemon, `diff-hook` must be set in the `nix.conf`
+    configuration file, and cannot be passed at the command line.
+
+  - `enforce-determinism`  
+    See [varlistentry\_title](#conf-repeat).
+
+  - `extra-sandbox-paths`  
+    A list of additional paths appended to `sandbox-paths`. Useful if
+    you want to extend its default value.
+
+  - `extra-platforms`  
+    Platforms other than the native one which this machine is capable of
+    building for. This can be useful for supporting additional
+    architectures on compatible machines: i686-linux can be built on
+    x86\_64-linux machines (and the default for this setting reflects
+    this); armv7 is backwards-compatible with armv6 and armv5tel; some
+    aarch64 machines can also natively run 32-bit ARM code; and
+    qemu-user may be used to support non-native platforms (though this
+    may be slow and buggy). Most values for this are not enabled by
+    default because build systems will often misdetect the target
+    platform and generate incompatible code, so you may wish to
+    cross-check the results of using this option against proper
+    natively-built versions of your derivations.
+
+  - `extra-substituters`  
+    Additional binary caches appended to those specified in
+    `substituters`. When used by unprivileged users, untrusted
+    substituters (i.e. those not listed in `trusted-substituters`) are
+    silently ignored.
+
+  - `fallback`  
+    If set to `true`, Nix will fall back to building from source if a
+    binary substitute fails. This is equivalent to the `--fallback`
+    flag. The default is `false`.
+
+  - `fsync-metadata`  
+    If set to `true`, changes to the Nix store metadata (in
+    `/nix/var/nix/db`) are synchronously flushed to disk. This improves
+    robustness in case of system crashes, but reduces performance. The
+    default is `true`.
+
+  - `hashed-mirrors`  
+    A list of web servers used by `builtins.fetchurl` to obtain files by
+    hash. The default is `http://tarballs.nixos.org/`. Given a hash type
+    ht and a base-16 hash h, Nix will try to download the file from
+    `hashed-mirror/ht/h`. This allows files to be downloaded even if
+    they have disappeared from their original URI. For example, given
+    the default mirror `http://tarballs.nixos.org/`, when building the
+    derivation
+    
+        builtins.fetchurl {
+          url = "https://example.org/foo-1.2.3.tar.xz";
+          sha256 = "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae";
+        }
+    
+    Nix will attempt to download this file from
+    `http://tarballs.nixos.org/sha256/2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae`
+    first. If it is not available there, if will try the original URI.
+
+  - `http-connections`  
+    The maximum number of parallel TCP connections used to fetch files
+    from binary caches and by other downloads. It defaults to 25. 0
+    means no limit.
+
+  - `keep-build-log`  
+    If set to `true` (the default), Nix will write the build log of a
+    derivation (i.e. the standard output and error of its builder) to
+    the directory `/nix/var/log/nix/drvs`. The build log can be
+    retrieved using the command `nix-store -l
+                    path`.
+
+  - `keep-derivations`  
+    If `true` (default), the garbage collector will keep the derivations
+    from which non-garbage store paths were built. If `false`, they will
+    be deleted unless explicitly registered as a root (or reachable from
+    other roots).
+    
+    Keeping derivation around is useful for querying and traceability
+    (e.g., it allows you to ask with what dependencies or options a
+    store path was built), so by default this option is on. Turn it off
+    to save a bit of disk space (or a lot if `keep-outputs` is also
+    turned on).
+
+  - `keep-env-derivations`  
+    If `false` (default), derivations are not stored in Nix user
+    environments. That is, the derivations of any build-time-only
+    dependencies may be garbage-collected.
+    
+    If `true`, when you add a Nix derivation to a user environment, the
+    path of the derivation is stored in the user environment. Thus, the
+    derivation will not be garbage-collected until the user environment
+    generation is deleted (`nix-env --delete-generations`). To prevent
+    build-time-only dependencies from being collected, you should also
+    turn on `keep-outputs`.
+    
+    The difference between this option and `keep-derivations` is that
+    this one is “sticky”: it applies to any user environment created
+    while this option was enabled, while `keep-derivations` only applies
+    at the moment the garbage collector is run.
+
+  - `keep-outputs`  
+    If `true`, the garbage collector will keep the outputs of
+    non-garbage derivations. If `false` (default), outputs will be
+    deleted unless they are GC roots themselves (or reachable from other
+    roots).
+    
+    In general, outputs must be registered as roots separately. However,
+    even if the output of a derivation is registered as a root, the
+    collector will still delete store paths that are used only at build
+    time (e.g., the C compiler, or source tarballs downloaded from the
+    network). To prevent it from doing so, set this option to `true`.
+
+  - `max-build-log-size`  
+    This option defines the maximum number of bytes that a builder can
+    write to its stdout/stderr. If the builder exceeds this limit, it’s
+    killed. A value of `0` (the default) means that there is no limit.
+
+  - `max-free`  
+    When a garbage collection is triggered by the `min-free` option, it
+    stops as soon as `max-free` bytes are available. The default is
+    infinity (i.e. delete all garbage).
+
+  - `max-jobs`  
+    This option defines the maximum number of jobs that Nix will try to
+    build in parallel. The default is `1`. The special value `auto`
+    causes Nix to use the number of CPUs in your system. `0` is useful
+    when using remote builders to prevent any local builds (except for
+    `preferLocalBuild` derivation attribute which executes locally
+    regardless). It can be overridden using the `--max-jobs` (`-j`)
+    command line switch.
+    
+    See also [???](#chap-tuning-cores-and-jobs).
+
+  - `max-silent-time`  
+    This option defines the maximum number of seconds that a builder can
+    go without producing any data on standard output or standard error.
+    This is useful (for instance in an automated build system) to catch
+    builds that are stuck in an infinite loop, or to catch remote builds
+    that are hanging due to network problems. It can be overridden using
+    the `--max-silent-time` command line switch.
+    
+    The value `0` means that there is no timeout. This is also the
+    default.
+
+  - `min-free`  
+    When free disk space in `/nix/store` drops below `min-free` during a
+    build, Nix performs a garbage-collection until `max-free` bytes are
+    available or there is no more garbage. A value of `0` (the default)
+    disables this feature.
+
+  - `narinfo-cache-negative-ttl`  
+    The TTL in seconds for negative lookups. If a store path is queried
+    from a substituter but was not found, there will be a negative
+    lookup cached in the local disk cache database for the specified
+    duration.
+
+  - `narinfo-cache-positive-ttl`  
+    The TTL in seconds for positive lookups. If a store path is queried
+    from a substituter, the result of the query will be cached in the
+    local disk cache database including some of the NAR metadata. The
+    default TTL is a month, setting a shorter TTL for positive lookups
+    can be useful for binary caches that have frequent garbage
+    collection, in which case having a more frequent cache invalidation
+    would prevent trying to pull the path again and failing with a hash
+    mismatch if the build isn't reproducible.
+
+  - `netrc-file`  
+    If set to an absolute path to a `netrc` file, Nix will use the HTTP
+    authentication credentials in this file when trying to download from
+    a remote host through HTTP or HTTPS. Defaults to
+    `$NIX_CONF_DIR/netrc`.
+    
+    The `netrc` file consists of a list of accounts in the following
+    format:
+    
+        machine my-machine
+        login my-username
+        password my-password
+    
+    For the exact syntax, see [the `curl`
+    documentation.](https://ec.haxx.se/usingcurl-netrc.html)
+    
+    > **Note**
+    > 
+    > This must be an absolute path, and `~` is not resolved. For
+    > example, `~/.netrc` won't resolve to your home directory's
+    > `.netrc`.
+
+  - `plugin-files`  
+    A list of plugin files to be loaded by Nix. Each of these files will
+    be dlopened by Nix, allowing them to affect execution through static
+    initialization. In particular, these plugins may construct static
+    instances of RegisterPrimOp to add new primops or constants to the
+    expression language, RegisterStoreImplementation to add new store
+    implementations, RegisterCommand to add new subcommands to the `nix`
+    command, and RegisterSetting to add new nix config settings. See the
+    constructors for those types for more details.
+    
+    Since these files are loaded into the same address space as Nix
+    itself, they must be DSOs compatible with the instance of Nix
+    running at the time (i.e. compiled against the same headers, not
+    linked to any incompatible libraries). They should not be linked to
+    any Nix libs directly, as those will be available already at load
+    time.
+    
+    If an entry in the list is a directory, all files in the directory
+    are loaded as plugins (non-recursively).
+
+  - `pre-build-hook`  
+    If set, the path to a program that can set extra derivation-specific
+    settings for this system. This is used for settings that can't be
+    captured by the derivation model itself and are too variable between
+    different versions of the same system to be hard-coded into nix.
+    
+    The hook is passed the derivation path and, if sandboxes are
+    enabled, the sandbox directory. It can then modify the sandbox and
+    send a series of commands to modify various settings to stdout. The
+    currently recognized commands are:
+    
+      - `extra-sandbox-paths`  
+        Pass a list of files and directories to be included in the
+        sandbox for this build. One entry per line, terminated by an
+        empty line. Entries have the same format as `sandbox-paths`.
+
+  - `post-build-hook`  
+    Optional. The path to a program to execute after each build.
+    
+    This option is only settable in the global `nix.conf`, or on the
+    command line by trusted users.
+    
+    When using the nix-daemon, the daemon executes the hook as `root`.
+    If the nix-daemon is not involved, the hook runs as the user
+    executing the nix-build.
+    
+      - The hook executes after an evaluation-time build.
+    
+      - The hook does not execute on substituted paths.
+    
+      - The hook's output always goes to the user's terminal.
+    
+      - If the hook fails, the build succeeds but no further builds
+        execute.
+    
+      - The hook executes synchronously, and blocks other builds from
+        progressing while it runs.
+    
+    The program executes with no arguments. The program's environment
+    contains the following environment variables:
+    
+      - `DRV_PATH`  
+        The derivation for the built paths.
+        
+        Example:
+        `/nix/store/5nihn1a7pa8b25l9zafqaqibznlvvp3f-bash-4.4-p23.drv`
+    
+      - `OUT_PATHS`  
+        Output paths of the built derivation, separated by a space
+        character.
+        
+        Example:
+        `/nix/store/zf5lbh336mnzf1nlswdn11g4n2m8zh3g-bash-4.4-p23-dev
+                                                                                                        /nix/store/rjxwxwv1fpn9wa2x5ssk5phzwlcv4mna-bash-4.4-p23-doc
+                                                                                                        /nix/store/6bqvbzjkcp9695dq0dpl5y43nvy37pq1-bash-4.4-p23-info
+                                                                                                        /nix/store/r7fng3kk3vlpdlh2idnrbn37vh4imlj2-bash-4.4-p23-man
+                                                                                                        /nix/store/xfghy8ixrhz3kyy6p724iv3cxji088dx-bash-4.4-p23`.
+    
+    See [???](#chap-post-build-hook) for an example implementation.
+
+  - `repeat`  
+    How many times to repeat builds to check whether they are
+    deterministic. The default value is 0. If the value is non-zero,
+    every build is repeated the specified number of times. If the
+    contents of any of the runs differs from the previous ones and
+    [varlistentry\_title](#conf-enforce-determinism) is true, the build
+    is rejected and the resulting store paths are not registered as
+    “valid” in Nix’s database.
+
+  - `require-sigs`  
+    If set to `true` (the default), any non-content-addressed path added
+    or copied to the Nix store (e.g. when substituting from a binary
+    cache) must have a valid signature, that is, be signed using one of
+    the keys listed in `trusted-public-keys` or `secret-key-files`. Set
+    to `false` to disable signature checking.
+
+  - `restrict-eval`  
+    If set to `true`, the Nix evaluator will not allow access to any
+    files outside of the Nix search path (as set via the `NIX_PATH`
+    environment variable or the `-I` option), or to URIs outside of
+    `allowed-uri`. The default is `false`.
+
+  - `run-diff-hook`  
+    If true, enable the execution of
+    [varlistentry\_title](#conf-diff-hook).
+    
+    When using the Nix daemon, `run-diff-hook` must be set in the
+    `nix.conf` configuration file, and cannot be passed at the command
+    line.
+
+  - `sandbox`  
+    If set to `true`, builds will be performed in a *sandboxed
+    environment*, i.e., they’re isolated from the normal file system
+    hierarchy and will only see their dependencies in the Nix store, the
+    temporary build directory, private versions of `/proc`, `/dev`,
+    `/dev/shm` and `/dev/pts` (on Linux), and the paths configured with
+    the [`sandbox-paths` option](#conf-sandbox-paths). This is useful to
+    prevent undeclared dependencies on files in directories such as
+    `/usr/bin`. In addition, on Linux, builds run in private PID, mount,
+    network, IPC and UTS namespaces to isolate them from other processes
+    in the system (except that fixed-output derivations do not run in
+    private network namespace to ensure they can access the network).
+    
+    Currently, sandboxing only work on Linux and macOS. The use of a
+    sandbox requires that Nix is run as root (so you should use the
+    [“build users” feature](#conf-build-users-group) to perform the
+    actual builds under different users than root).
+    
+    If this option is set to `relaxed`, then fixed-output derivations
+    and derivations that have the `__noChroot` attribute set to `true`
+    do not run in sandboxes.
+    
+    The default is `true` on Linux and `false` on all other platforms.
+
+  - `sandbox-dev-shm-size`  
+    This option determines the maximum size of the `tmpfs` filesystem
+    mounted on `/dev/shm` in Linux sandboxes. For the format, see the
+    description of the `size` option of `tmpfs` in mount8. The default
+    is `50%`.
+
+  - `sandbox-paths`  
+    A list of paths bind-mounted into Nix sandbox environments. You can
+    use the syntax `target=source` to mount a path in a different
+    location in the sandbox; for instance, `/bin=/nix-bin` will mount
+    the path `/nix-bin` as `/bin` inside the sandbox. If source is
+    followed by `?`, then it is not an error if source does not exist;
+    for example, `/dev/nvidiactl?` specifies that `/dev/nvidiactl` will
+    only be mounted in the sandbox if it exists in the host filesystem.
+    
+    Depending on how Nix was built, the default value for this option
+    may be empty or provide `/bin/sh` as a bind-mount of `bash`.
+
+  - `secret-key-files`  
+    A whitespace-separated list of files containing secret (private)
+    keys. These are used to sign locally-built paths. They can be
+    generated using `nix-store
+                    --generate-binary-cache-key`. The corresponding public key can be
+    distributed to other users, who can add it to `trusted-public-keys`
+    in their `nix.conf`.
+
+  - `show-trace`  
+    Causes Nix to print out a stack trace in case of Nix expression
+    evaluation errors.
+
+  - `substitute`  
+    If set to `true` (default), Nix will use binary substitutes if
+    available. This option can be disabled to force building from
+    source.
+
+  - `stalled-download-timeout`  
+    The timeout (in seconds) for receiving data from servers during
+    download. Nix cancels idle downloads after this timeout's duration.
+
+  - `substituters`  
+    A list of URLs of substituters, separated by whitespace. The default
+    is `https://cache.nixos.org`.
+
+  - `system`  
+    This option specifies the canonical Nix system name of the current
+    installation, such as `i686-linux` or `x86_64-darwin`. Nix can only
+    build derivations whose `system` attribute equals the value
+    specified here. In general, it never makes sense to modify this
+    value from its default, since you can use it to ‘lie’ about the
+    platform you are building on (e.g., perform a Mac OS build on a
+    Linux machine; the result would obviously be wrong). It only makes
+    sense if the Nix binaries can run on multiple platforms, e.g.,
+    ‘universal binaries’ that run on `x86_64-linux` and `i686-linux`.
+    
+    It defaults to the canonical Nix system name detected by `configure`
+    at build time.
+
+  - `system-features`  
+    A set of system “features” supported by this machine, e.g. `kvm`.
+    Derivations can express a dependency on such features through the
+    derivation attribute `requiredSystemFeatures`. For example, the
+    attribute
+    
+        requiredSystemFeatures = [ "kvm" ];
+    
+    ensures that the derivation can only be built on a machine with the
+    `kvm` feature.
+    
+    This setting by default includes `kvm` if `/dev/kvm` is accessible,
+    and the pseudo-features `nixos-test`, `benchmark` and `big-parallel`
+    that are used in Nixpkgs to route builds to specific machines.
+
+  - `tarball-ttl`  
+    Default: `3600` seconds.
+    
+    The number of seconds a downloaded tarball is considered fresh. If
+    the cached tarball is stale, Nix will check whether it is still up
+    to date using the ETag header. Nix will download a new version if
+    the ETag header is unsupported, or the cached ETag doesn't match.
+    
+    Setting the TTL to `0` forces Nix to always check if the tarball is
+    up to date.
+    
+    Nix caches tarballs in `$XDG_CACHE_HOME/nix/tarballs`.
+    
+    Files fetched via `NIX_PATH`, `fetchGit`, `fetchMercurial`,
+    `fetchTarball`, and `fetchurl` respect this TTL.
+
+  - `timeout`  
+    This option defines the maximum number of seconds that a builder can
+    run. This is useful (for instance in an automated build system) to
+    catch builds that are stuck in an infinite loop but keep writing to
+    their standard output or standard error. It can be overridden using
+    the `--timeout` command line switch.
+    
+    The value `0` means that there is no timeout. This is also the
+    default.
+
+  - `trace-function-calls`  
+    Default: `false`.
+    
+    If set to `true`, the Nix evaluator will trace every function call.
+    Nix will print a log message at the "vomit" level for every function
+    entrance and function exit.
+    
+    <div class="informalexample">
+    
+        function-trace entered undefined position at 1565795816999559622
+        function-trace exited undefined position at 1565795816999581277
+        function-trace entered /nix/store/.../example.nix:226:41 at 1565795253249935150
+        function-trace exited /nix/store/.../example.nix:226:41 at 1565795253249941684
+    
+    </div>
+    
+    The `undefined position` means the function call is a builtin.
+    
+    Use the `contrib/stack-collapse.py` script distributed with the Nix
+    source code to convert the trace logs in to a format suitable for
+    `flamegraph.pl`.
+
+  - `trusted-public-keys`  
+    A whitespace-separated list of public keys. When paths are copied
+    from another Nix store (such as a binary cache), they must be signed
+    with one of these keys. For example:
+    `cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
+                    hydra.nixos.org-1:CNHJZBh9K4tP3EKF6FkkgeVYsS3ohTl+oS0Qa8bezVs=`.
+
+  - `trusted-substituters`  
+    A list of URLs of substituters, separated by whitespace. These are
+    not used by default, but can be enabled by users of the Nix daemon
+    by specifying `--option
+                    substituters urls` on the command line. Unprivileged users are only
+    allowed to pass a subset of the URLs listed in `substituters` and
+    `trusted-substituters`.
+
+  - `trusted-users`  
+    A list of names of users (separated by whitespace) that have
+    additional rights when connecting to the Nix daemon, such as the
+    ability to specify additional binary caches, or to import unsigned
+    NARs. You can also specify groups by prefixing them with `@`; for
+    instance, `@wheel` means all users in the `wheel` group. The default
+    is `root`.
+    
+    > **Warning**
+    > 
+    > Adding a user to `trusted-users` is essentially equivalent to
+    > giving that user root access to the system. For example, the user
+    > can set `sandbox-paths` and thereby obtain read access to
+    > directories that are otherwise inacessible to them.
+
+## Deprecated Settings
+
+  - `binary-caches`  
+    *Deprecated:* `binary-caches` is now an alias to
+    [varlistentry\_title](#conf-substituters).
+
+  - `binary-cache-public-keys`  
+    *Deprecated:* `binary-cache-public-keys` is now an alias to
+    [varlistentry\_title](#conf-trusted-public-keys).
+
+  - `build-compress-log`  
+    *Deprecated:* `build-compress-log` is now an alias to
+    [varlistentry\_title](#conf-compress-build-log).
+
+  - `build-cores`  
+    *Deprecated:* `build-cores` is now an alias to
+    [varlistentry\_title](#conf-cores).
+
+  - `build-extra-chroot-dirs`  
+    *Deprecated:* `build-extra-chroot-dirs` is now an alias to
+    [varlistentry\_title](#conf-extra-sandbox-paths).
+
+  - `build-extra-sandbox-paths`  
+    *Deprecated:* `build-extra-sandbox-paths` is now an alias to
+    [varlistentry\_title](#conf-extra-sandbox-paths).
+
+  - `build-fallback`  
+    *Deprecated:* `build-fallback` is now an alias to
+    [varlistentry\_title](#conf-fallback).
+
+  - `build-max-jobs`  
+    *Deprecated:* `build-max-jobs` is now an alias to
+    [varlistentry\_title](#conf-max-jobs).
+
+  - `build-max-log-size`  
+    *Deprecated:* `build-max-log-size` is now an alias to
+    [varlistentry\_title](#conf-max-build-log-size).
+
+  - `build-max-silent-time`  
+    *Deprecated:* `build-max-silent-time` is now an alias to
+    [varlistentry\_title](#conf-max-silent-time).
+
+  - `build-repeat`  
+    *Deprecated:* `build-repeat` is now an alias to
+    [varlistentry\_title](#conf-repeat).
+
+  - `build-timeout`  
+    *Deprecated:* `build-timeout` is now an alias to
+    [varlistentry\_title](#conf-timeout).
+
+  - `build-use-chroot`  
+    *Deprecated:* `build-use-chroot` is now an alias to
+    [varlistentry\_title](#conf-sandbox).
+
+  - `build-use-sandbox`  
+    *Deprecated:* `build-use-sandbox` is now an alias to
+    [varlistentry\_title](#conf-sandbox).
+
+  - `build-use-substitutes`  
+    *Deprecated:* `build-use-substitutes` is now an alias to
+    [varlistentry\_title](#conf-substitute).
+
+  - `gc-keep-derivations`  
+    *Deprecated:* `gc-keep-derivations` is now an alias to
+    [varlistentry\_title](#conf-keep-derivations).
+
+  - `gc-keep-outputs`  
+    *Deprecated:* `gc-keep-outputs` is now an alias to
+    [varlistentry\_title](#conf-keep-outputs).
+
+  - `env-keep-derivations`  
+    *Deprecated:* `env-keep-derivations` is now an alias to
+    [varlistentry\_title](#conf-keep-env-derivations).
+
+  - `extra-binary-caches`  
+    *Deprecated:* `extra-binary-caches` is now an alias to
+    [varlistentry\_title](#conf-extra-substituters).
+
+  - `trusted-binary-caches`  
+    *Deprecated:* `trusted-binary-caches` is now an alias to
+    [varlistentry\_title](#conf-trusted-substituters).
diff --git a/doc/manual/src/command-ref/files.md b/doc/manual/src/command-ref/files.md
new file mode 100644
index 000000000..df5646c05
--- /dev/null
+++ b/doc/manual/src/command-ref/files.md
@@ -0,0 +1,4 @@
+# Files
+
+This section lists configuration files that you can use when you work
+with Nix.