(Replying to PARENT post)
If anyone is curious about what the books say, US Air Traffic Controllers use phraseology prescribed by FAA General Order 7110.65.
Also known as the 7110 or the point sixty-five, it includes rules that Air Traffic Controllers must follow to ensure safe and effective operations. So if you're a pilot and are wondering why you have a Hold For Release or are told "unable", you might find the reason in this document.
The Wikipedia article [0] links the PDF version as well as the online version.
👤TangoFox🕑4y🔼0🗨️0
(Replying to PARENT post)