negative squared latin capital letter p symbol.
Copy and paste this emoji:
symbol
P button was assigned codepoint in Unicode 5.2 on 01 October 2009.
P button was included in Emoji 1.0 on 04 August 2015.
🅿 U+1F17F
:parking:
🈵 Japanese “no vacancy” button
🈺 Japanese “open for business” button