Hmmm - I do find it mildly amusing to have a poll to prove me wrong - I've been in Congress House this morning, and found this much more interesting than Fit Notes
I've been looking in all the diving books i have, and notice one thing that is common in every formula that is produced. No matter what symbols are used within the formula, there is a little code at the end of it.
P, I have noticed is used to denote, in various different formulae, Pressure at ambient, Pressure in BAR/ata, Partial pressure, Absolute pressure and a whole host of others. Never percentage. So - I seem to be wrong. I will tell myself off, punish myself severly and stand in the corner

The OP seemed particularly concerned that I might be actually teaching it wrongly. To be honest - when i teach this stuff, I have the formulae written down, and the little key's with it, so I don't think i have ever taught that, as it wouldn't be that way in the materials the students have.
However, In normal circumstances, if I am referring to Partial Pressure of Oxygen, then it is
always, for me, PPO2.
So - the poll is wrong
