UIDS-GIDS.md: explicitly mention one more user of the overflowuid

File systems with only 16bit UID support (i.e. old ext2) also use the
overflowuid to map users they can't map. Briefly mention this.

diff --git a/UIDS-GIDS.md b/UIDS-GIDS.md
index 71e91faa6a92efea92e040c9af9429ffeab6ef3f..e19cc88162378b40c935639daa69c9f64923b8cc 100644 (file)
--- a/UIDS-GIDS.md
+++ b/UIDS-GIDS.md
@@ -17,13 +17,14 @@ i.e. 0…4294967295. However, four UIDs are special on Linux:
 1. 0 → The `root` super-user
 
 2. 65534 → The `nobody` UID, also called the "overflow" UID or similar. It's
-   where various subsystems map unmappable users to, for example NFS or user
-   namespacing. (The latter can be changed with a sysctl during runtime, but
-   that's not supported on `systemd`. If you do change it you void your
-   warranty.) Because Fedora is a bit confused the `nobody` user is called
-   `nfsnobody` there (and they have a different `nobody` user at UID 99). I
-   hope this will be corrected eventually though. (Also, some distributions
-   call the `nobody` group `nogroup`. I wish they didn't.)
+   where various subsystems map unmappable users to, for example file systems
+   only supporting 16bit UIDs, NFS or user namespacing. (The latter can be
+   changed with a sysctl during runtime, but that's not supported on
+   `systemd`. If you do change it you void your warranty.) Because Fedora is a
+   bit confused the `nobody` user is called `nfsnobody` there (and they have a
+   different `nobody` user at UID 99). I hope this will be corrected eventually
+   though. (Also, some distributions call the `nobody` group `nogroup`. I wish
+   they didn't.)
 
 3. 4294967295, aka "32bit `(uid_t) -1`" → This UID is not a valid user ID, as
    `setresuid()`, `chown()` and friends treat -1 as a special request to not