You may have come here looking for Tk's bell command, which sounds an audible alert. This page is rather about BEEP, the Blocks Extensible Exchange Protocol.
[RFC 3080 says "a generic application protocol kernel for connection-oriented, asynchronous interactions called the BEEP (Blocks Extensible Exchange Protocol) core. BEEP permits simultaneous and independent exchanges within the context of a single application user-identity, supporting both textual and binary messages."]
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