-&:local+global [&]VARIABLE ...
- Suppresses the warning about seeing both VARIABLE and
- &VARIABLE. Any & specified in the RHS is redundant: this
- always affects both versions identically.
+&:local+global [!][&]VARIABLE ...
+ Suppresses any warnings relating to forthcoming mentions
+ to VARIABLE or &VARIABLE, as applicable. Scope ends at
+ the end of the current directory's Suffix.sd.mk.
+ Prefixing with ! removes [&]VARIABLE from the suppresion list.