Use "foo" to refer to formal parameters when documenting
procedures or operators.
Use `whatever' to refer to any other source construct that is
not a formal parameter.
Use {{ and }} delimiters for commenting out code.
Remember comments in modern Algol 68 aren’t nestable.
Examples:
int error_hash = 0;
{ Return a hash code for the string "s", or `error_hash' if the string
is too long. }
proc hash_string (string s)
{{ int no_longer_needed; }}