The question of what is a valid parameter, action or keyword name is rather
complicated.
It is affected by Interface File parsing, the parameter system, HDS and the
particular user interface in use.
Appendix gives the maximum lengths allowed and, to avoid problems,
it is recommended that names begin with a letter and continue with true
alphanumeric characters or underscore.
Parameter, action and keyword names are converted to upper case for storage. If they are displayed, in prompts or error messages etc., they will appear in upper case.
ADAM Interface Module Reference Manual