xyw follows a few simple conventions aimed at making programs more coherent and readable. macros not resolving to an address: UPPERCASE label/macro resolving to an address: lowercase spare zero-page address (byte): z.<name> device registers: <device>.<name> sublabels: <label>.<name> macro consuming a word: ends with w subroutine: start with verb (unless a getter) subroutine consuming a word: ends with _w word value: ends with _w (or _W) address of string: ends with _s pointer to address: start with _ word separator: _ macro names must not clash with instruction mnemonics optionally followed by x/y/w stack effects should be documented with comments above subroutines (see notation) device names (system, terminal, clock, file, beeper) are reserved and can only be used in device register macros === Examples prompt_s -> address of a string file._path_s -> register holding an address of a string system._on_error -> register pointing to an address z.mode -> address of a byte stored on zero page z.size_w -> address of a word stored on zero page DBGw -> macro consuming a two-byte value ARG_SEP -> macro resolving to a byte value DBGw -> macro consuming a word MAX_SIZE_W -> macro resolving to a word value handle_keypress -> subroutine handle_keypress.check -> sublabel within subroutine length_w -> subroutine returning a word or label to word value