Some equipment uses a modification of the original balanced standard, in which pin 2 is non-inverting. Sometime in the 70s or 80s, European equipment went to pin 3 non-inverting. This practice has shown up in some Japanese equipment as well. This stuff is all over the industry! Unless someone has taken the time to make special cables that convert from the pin 2 convention to the pin 3 convention, the result is there is simply no way to know what is up.Atmasphere raises a very important point here, that is the difference between the "American" (pin 2 hot) and "European" (pin 3 hot) XLR pinouts. The "American" pinout is the EIA/AES specified professional standard, but this is of course not at all consistent across different types of gear, i.e. microphones are virtually always wired with pin 2 hot.
I didn't mean to imply that recording and mastering engineers in general give any special attention to absolute phase, but as others has pointed out, relative phase is absolutely critical. So in practice, when outboard gear in the studio (i.e. a compressor, mic preamp, effects unit, etc.) is wired to the patchbay or console, any potential polarity reversals *should* be corrected. Otherwise, this can cause some really weird issues when the output is brought back into the console for mixdown, or routed to headphones on tracking.
So a thorough, necessary attention to relative phase is highly necessary, and absolute phase much of the time just comes along with the ride. This is especially true given the ubiquity of Pro Tools . . . when one purchases a CD that's digitally recorded, mixed, and mastered, it's a pretty good bet that a positive pulse on the vast majority of input channels' (microphones') ADC corresponds to a positive pulse on the output of your CD player.