With this mutator you can do one or both of these:
A. CTF Flags: It lets you put your own custom textures onto the CTF flags. This includes when the flag is carried or dropped.
B. Decoration Flags: It lets you put what appears to be a CTF flag into non-CTF maps, with textures of your making, as a decoration.
Full instructions in the download.
http://www.birdieman.com/downloads/medFlag.rar