english
1
general::
Phrase(s): keep someone posted Fig. to keep someone informed (of what is happening); to keep someone up to date. • If the price of corn goes up, I need to know. Please keep me posted. • Keep her posted about the patient’s status.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Supply with up-to-date information, as in Keep me posted about your new job. This usage alludes to the accounting practice of posting the latest figures in a ledger. [Early 1800s]
American Heritage Idioms