Select Setup > Preferences > Import/Export. Here you can specify whether you wish to be prompted for a comment or not. If you elect NOT be to prompted, you have the further option of specifying "no comment" or a fixed comment of your choosing, e.g. "This RTL object compliments of Charles Dow". The comment exported with the RTL object is displayed to the recipient when someone imports your scan, signal, or custom indicator. If you wish to add more detailed textual comments to a specific RTL object, add text anywhere you like inside the formula area of the RTL setup. e.g.
CL > MA; /* find instruments trading above their 100 day moving average */
Any text in the syntax area that is preceded with /* and terminated by */ is ignored by the parser and treated as commentary.
Example
/* this is a comment */ CL > MA; /* and so is this */
The above does the same as CL > MA