[PATCH] doc: Document that kernel may accept unimplemented expressions

[Topi Miettinen <toiwoton@gmail.com>]

Kernel silently accepts input chain filters using meta skuid, meta
skgid, meta cgroup or socket cgroupv2 expressions but they don't work
yet. Warn the users of this possibility.

Signed-off-by: Topi Miettinen <toiwoton@gmail.com>
---
 doc/nft.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/doc/nft.txt b/doc/nft.txt
index f7a53ac9..4820b4ae 100644
--- a/doc/nft.txt
+++ b/doc/nft.txt
@@ -932,6 +932,11 @@ filter output oif wlan0
 ^^^^^^^^^^^^^^^^^^^^^^^
 ---------------------------------
 
+Note that the kernel may accept expressions without errors even if it
+doesn't implement the feature. For example, input chain filters using
+*meta skuid*, *meta skgid*, *meta cgroup* or *socket cgroupv2*
+expressions are silently accepted but they don't work yet.
+
 EXIT STATUS
 -----------
 On success, nft exits with a status of 0. Unspecified errors cause it to exit

base-commit: 6fa4ff56385831f01bd9d993178969a4eddbcdbf
-- 
2.35.1