.38 Special +P - Indicators/determination

[Dannyboy]

Folks,

I've been refreshing my knowledge about .38 Specials, and the option to fire +P ammo.

Is there an industry standard the manufactures use to tells us if a gun is or isn't +P rated? A special mark, or something in the serial number?

For example, one of my pistols is a 1993 Taurus Model 85 B2. I ran the serial on Rossi's tech site, but the only info it returned was the exact model. I'm assuming that the manual that came with the original box may make reference to the +P rating if it's there. But of course in this day and age, buying used firearms often lacks the manual.

Just wondering if Taurus or ANY of the makers use an common industry standard so that we know these things. I googled it, and word is that it's +P rated, but I'd rather be told directly by the maker. Thanks for any input.