Pill Identification by Imprints: P F Home Pill Identification by Imprints: P F 2 results THEOPHYLLINE ER 400 MG TABLET Side 1: U 400 Color: White Side 2: P F Shape: Round THEOPHYLLINE ER 600 MG TABLET Side 1: P F Color: White Side 2: U 600 Shape: Rectangular Other Popular Drug Imprint Z or M CTI 122 VALTREX 1 gram M 573 TCL341 I 37 ATABEX par 009 LCE 50 PD 237 L 105 75mg 50 mg 85 U48 X X 8 MSD 106 WP M 3 DXL logo and 4365 E5254 54 373 STO 50 EK 10 APO TI-2 CH VISMO NL 792 PTLA MYLAN 6750 MUTUAL 100 R531 M P5 G 531 2773 cor 215 R1 113