PO3 may refer to::
*
Phosphite
The general structure of a phosphite ester showing the lone pairs on the P
In organic chemistry, a phosphite ester or organophosphite usually refers to an organophosphorous compound with the formula P(OR)3. They can be considered as esters of ...
*
Petty officer third class
A Petty officer third class is a non-commissioned officer in some navies and coast guards.
By country
United States
Petty officer third class is the fourth enlisted rank in the United States Navy, U.S. Navy and the United States Coast Guard, ...
* PO3: an EEG electrode site according to the
10-20 system
* A videogame character from
Inscryption
''Inscryption'' is a 2021 roguelike deck-building game developed by Daniel Mullins Games and published by Devolver Digital. Directed by Daniel Mullins, it was originally released for Windows on October 19, 2021, and on Linux, macOS, PlayStation 4 ...
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