Sign of La Forge
The "Sign of La Forge" was a good omen invented by Lieutenant Worf in 2370, named for Lieutenant Commander Geordi La Forge. It consisted of a set of crisscrossing horizontal and vertical yellow lines on a black background, appearing as a faint image in water. Worf claimed it appeared to travelers as a sign of good luck and fortune.

In reality, Worf was masquerading as a Boraalan seer while the group was being moved from Boraal II to Vacca VI on the  holodeck. The hologrid became visible to a Boraalan, and Worf improvised the term to explain the malfunction and alert La Forge, who had been monitoring the situation over a communications channel, to the problem. ()
Mythology
Fictional