Often used to tell new or inexperienced users on 4chan's /b/ image board to search further into the depths of /b/ to find things such as the origin of certain memes, or just to stop posting until they are more familiar with /b/.
Noob: LoLz sniper kitty roXors my soXors. who make it in first place?!/!!1?
/b/: LURK MOAR.