Why are these 10K 1% resistors marked with '103' which is the 3-digit marking for a 5% resistor? Did we somehow receive 5% resistors? We expected 4-digit markings for these 1% resistors, which would be '1002' for this part.

This marking scheme would be true for MCR10 (0805) and larger body resistors, however the small size of the MCR03 (0603) series can only accommodate three digit markings. All 1% MCR03 series resistors that can be marked with 3-digits will be marked as such (the last significant digit is a zero). For all 1% MCR03 resistors requiring a full 4-digit code will be left blank (see E-96 values in the short form). All resistor values are clearly marked on the ROHM barcode labels found on the reels. Resistors smaller than MCR03, such as MCR01 (0402) and MCR006 (0201) have no markings and are blank for all values.