&CAPS => subdir_CAPS or TOP_CAPS &lc => subdir/lc or lc &_ => subdir_ or TOP_ &/ => subdir/ or nothing &=_ => subdir or TOP &=/ => subdir or . &^ => $(top_srcdir)/subdir or $(top_srcdir) &~ => $(abs_top_srcdir)/subdir or $(abs_top_srcdir) && => && \& => & & thing thing... & => each thing prefixed by &/ &^/ &~/ resp & ^ thing thing... & each thing is any non-ws & ~ thing thing... & & may be omitted before EOL or before \EOL other &'s not recognised CAPS is [A-Z][0-9_A-Z]*(?!\w) lc is [a-z][-+,0-9_a-z]*(?!\w) &! disables & *until* EOL (and disappears) &!STUFF STUFF is recognised instead of & the terminating lwsp is discarded too may also occur at eol eg notably STUFF!& now & is recognised instead (ie back to normal) STUFFSTUFF STUFF eg &!@@@ @@@ is recognised instead of & @@@!& go back to & &TARGETS[_things] is handled specially must be spelled precisely this way if no _things, means _all Also, `all' is weird in that it is present even if not specified