Update the S_IFMT godoc.
diff --git a/stat.go b/stat.go
index a34a98f..2bb2c13 100644
--- a/stat.go
+++ b/stat.go
@@ -85,5 +85,10 @@
s_ISVTX = uint32(sshfx.ModeSticky)
)
-// S_IFMT is a legacy export. `sshfx.ModeType` should be used instead
+// S_IFMT is a legacy export, and was brought in to support GOOS environments whose sysconfig.S_IFMT may be different from the value used internally by SFTP standards.
+// There should be no reason why you need to import it, or use it, but unexporting it could cause code to break in a way that cannot be readily fixed.
+// As such, we continue to export this value as the value used in the SFTP standard.
+//
+// Deprecated: Remove use of this value, and avoid any future use as well.
+// There is no alternative provided, you should never need to access this value.
const S_IFMT = uint32(sshfx.ModeType)
