EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH
Identifiers or Labels
A label begins with a letter, followed by up to fifteen letters,
digits, decimal points (.),
or underscores (_).
Characters beyond the sixteenth are dropped, but should be avoided,
and the resulting sequence must be unique.
A label may refer to a keyword, an element,
a beam-line, a sequence, etc.
The MAD-X keywords are protected; using one of them as a label results
in a fatal error.
hansg,
May 8, 2001