You want to suppress a rule without permanently removing it from the ruleset.
Use the suppress command to suppress a rule.
suppress gen_id , sid_id
Suppression allows you to deactivate a rule completely. The options are gen_id and sig_id. Gen_id is the generator ID, and sig_id is the Snort signature ID.
To suppress an event entirely:
suppress gen_id 1, sig_id 1234
Snort User Manual
Installing Snort from Source on Unix
Logging to a File Quickly
How to Build Rules
Detecting Stateless Attacks and Stream Reassembly
Managing Snort Sensors
Generating Statistical Output from Snort Logs
Monitoring Network Performance