ISO Pascal reference manual

Chapter 5
PROGRAM warn(output);
LABEL 1;
PROCEDURE jump; BEGIN
END;
BEGIN
GOTO 1;
jump;
1: writeln('here');
END.
Warning 85 -- this case label is out of range
Surprisingly, the Pascal standard does not proscribe the specification of case
labels which are outside the range of the case selector except when the
CASE is used to define record variants.
PROGRAM fail(output,input);
TYPE small = 1..3;
rec = RECORD CASE s:small OF
VAR tiny:small;
BEGIN
END.
read(tiny);
CASE tiny OF
END;
END;
1: writeln('one');
2: writeln('two');
3: writeln('three');
1: (a:integer);
2: (b:char);
3: (c:real);
4: (d:boolean); [error 4 is not in small)
4: writeln('four'); (warning 4 is not in small)
Warning 89 -- the case statement did not include all possible cases
A case statement has been found which has not provided a meaning for all
the possible values of the case selector. When this occurs in a RECORD
definition it is an error. When it occurs in a CASE statement it is only a
warning, however if the case selector takes one of the unspecified values
during execution a run-time error will be reported.
24 Pascal Issue 1