The Stock Messaging Application on Sprint LG Rumor Reflex LN272 support adding a customized text message signature.
To set up text message signature on LG Rumor Reflex LN272, Follow below simple step by step instruction:
Step 1. From Home Screen, Touch 
Step 2. Tap Main Menu -> Messaging -> Settings -> Signature
Step 3. Select Custom (If you do not wish to attach signature, Select None.)
Step 4. Enter a signature and Touch Save.
Enjoy your LG Rumor Reflex LN272 Cell Phone.