I do not know if the "six-one-two" is actually correct.
The imprint simply has a straight vertical line (not a score mark) between the 6 and 2, so it literally looks like a small case "l" (letter L). Perhaps "6-l-2"? No. I do not think that's correct given "regular" imprint standards.
Several of these were mixed in my new prescription bottle of generic Claritin (Loratadine). The pills I normally get are round, white, GG296. (These were also in the bottle).
There were no stickers on the bottle or bag from my pharmacist indicating a pill change.