13 RETAINING CLIPS FOR USE WITH SIGNS AND SIGNBOARDS, RETAINING CLIPS FOR LETTERS AND NUMERALS AND SYMBOLS AND INDICIA USED WITH SIGNS AND SIGNBOARDS, FRICTION CLIPS FOR USE WITH SIGNS AND SIGNBOARDS, FRICTION CLIPS FOR USE WITH LETTERS AND NUMERALS AND SYMBOLS AND INDICIA FOR SIGNS AND SIGNBOARDS, TRACKS FOR USE WITH SIGNS AND SIGNBOARDS, SINGLE-ENDED FASTENERS FOR USE WITH SIGNS AND SIGNBOARDS, AND DOUBLE-ENDED FASTENERS FOR USE WITH SIGNS AND SIGNBOARDS