There are no reserved words in PL/I. A statement is terminated by a semi-colon. The maximum length of a statement is implementation defined. A comment may appear anywhere in a program where a space is permitted and is preceded by the characters forward slash, asterisk and is terminated by the characters asterisk, forward slash (i.e. ). Statements may have a label-prefix introducing an entry name (codice_10 and codice_11 statements) or label name, and a condition prefix enabling or disabling a computational condition e.g. codice_12). Entry and label names may be single identifiers or identifiers followed by a subscript list of constants (as in codice_13).