+.Sh BUGS
+Some of these might be considered otherwise-undocumented features.
+.Pp
+.Nm compress :
+If the utility does not compress a file because doing so would not
+reduce its size, and a file of the same name except with an
+.Pa .Z
+extension exists, the named file is not really ignored as stated above;
+it causes a prompt to confirm the overwriting of the file with the extension.
+If the operation is confirmed, that file is deleted.
+.Pp
+.Nm uncompress :
+If an empty file is compressed (using
+.Fl f ) ,
+the resulting
+.Pa .Z
+file is also empty.
+That seems right, but if
+.Nm uncompress
+is then used on that file, an error will occur.
+.Pp
+Both utilities: If a
+.Sq Fl
+argument is used and the utility prompts the user, the standard input
+is taken as the user's reply to the prompt.
+.Pp
+Both utilities:
+If the specified file does not exist, but a similarly-named one with (for
+.Nm compress )
+or without (for
+.Nm uncompress )
+a
+.Pa .Z
+extension does exist, the utility will waste the user's time by not
+immediately emitting an error message about the missing file and
+continuing.
+Instead, it first asks for confirmation to overwrite
+the existing file and then does not overwrite it.