options: l: local extensions enabled n: no register messages s: symmetric range for integers: MIN(INTEGER) = -MAX(INTEGER) w: disable warnings x: make every name global (for ADB) A: extra array bound checks I: look in directory for definition modules L: no FIL/LIN instructions M: maximum identifier length R: runtime checks U: allow underscores in identifiers V: object sizes and alignments W: enable warnings 3: strict 3rd edition Modula-2 -: to pass debugging options Debugging options: i: display number of structures allocated and number of lines read t: run lexical analyzer only C: dump of constant expressions F: display size of every file read. S: define/lookup symbol table access dump X: parse-tree dump