What does shrtft1 mean on obd?

I believe you may be referring to Mode 1 PID 6. "shrft1" would be an abbreviation used by the software running on your scan tool or computer presumably to deal with limited area on the display.

Mode 1 PID 6 is commonly known as Short term fuel trim bank one. The short term trim indicates how much (as a percentage) the computer is enriching (positive values) or enleaning (negative values) the commanded fuel relative to how much it has recently (long term trim) needed in similar operating conditions.