📖What it means

WhatsApp's delivery rule: a free-form message from Carol is delivered only inside 24 hours of the person's OWN last message to her. Outside it the send is ACCEPTED — an id comes back — and arrives nowhere. The window is read from the send ledger: open, closed (with the age of their last message), or never-wrote; an UNREADABLE window is unmeasured, never open. Email has no messaging window.

📖Easily confused with

[{"term": "Context window", "distinction": "A model's context window is how much text fits in a prompt \u2014 a different thing entirely."}]

📖Nuance

Holding a number is not being able to reach somebody (rule 1668): code deciding whether to write to someone asks whether a conversation can be OPENED, never whether a number exists.

📖Also called

- 24-hour window
- conversation window

📖Filed under

Category: communications.

Service: Communications.