Edit

IncrementUserSeq (key)

Result Type: string

Definition: Atomically increments the User.Data value of a user record identified by key (creating the record with a data value of 0 if it does not already exist). Returns the incremented value. Although User.Data is a text field, IncrementUserSeq will increment the numeric part of it if it has a non-numeric prefix or suffix.

To set an initial value for a sequence, you can use SetPersistent("user", key, NULL, CreateArray("Data", initialValue))

Example:  

constant key = "MYSEQ"

on Load
    // set initial value
    SetPersistent("user", key, NULL, CreateArray("Data", "XY-998-Z"))
    // increment 3 times
    Syslog(IncrementUserSeq(key))
    Syslog(IncrementUserSeq(key))
    Syslog(IncrementUserSeq(key))

//    values returned:
//
//    XY-999-Z
//    XY-1000-Z
//    XY-1001-Z

end
Import Int