PC.net

OO

Meaning Over and out
Type Acronym
Popularity ★ ★ ★ ★ ☆  Common
Usage Online Only (chat, messaging, e-mail)
Comments

Used when signing off from an email message or online chat session; also OAO and O&O.

Updated February 22, 2013
Meaning On order
Type Acronym
Popularity ★ ★ ★ ☆ ☆  Average
Usage General (not just online)
Comments

Refers to a product that has been ordered, but has not arrived yet. May be seen on e-commerce sites or in order status reports.

Updated November 27, 2013
Meaning OpenOffice
Type Abbreviation
Popularity ★ ★ ☆ ☆ ☆  Uncommon
Usage Online Only (chat, messaging, e-mail)
Comments

An open-source productivity suite, similar to Microsoft Office. Technically referred to as "OpenOffice.org."

Updated November 27, 2013
Information from PC.net
https://pc.net/slang/meaning/oo
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