Name
A name consists of letters, digits and underscore characters. The first character must be a letter. The syntax for a name is:
<name> ::= <letter> {<letter>| <letter> | <digit> | _ }
Example
car michael a38 another_name_with_1_digit
The following names are pre-defined keywords and must not be employed as user-defined identifiers:
assign do_section_of not sound
category exit parameter startstr
clear_all int restore_values type
clear_value known rules unknown