What notation do constructed sign languages use?
Many well-known big sign languages (such as ASL) have their own form of notation, but that notation is very specific and may not be able to express a sign in other sign languages. For example, ASL school is
OpenB@Palm-PalmDown-OpenB@CenterChesthigh-PalmUp Contact Contact
but some constructed sign language X might require signals that don't appear in ASL, like 'touch your elbow with the thumb of your non-dominant hand'. The notation could be extended but would be complicating it. Language X thus requires its own system for its own signs or an 'international' one in analogy with the International Phonetic Alphabet.
What are the notations commonly used by constructed sign languages?
Which sign languages use them?