A +key/-key list edit (CASC.md §8.4) whose base or operand is not known until resolution -- +hosts = ${EXTRA_HOSTS[]}, or an append to a list that is itself a reference. Applied once both sides resolve.
+key
-key
+hosts = ${EXTRA_HOSTS[]}
for error messages
A
+key/-keylist edit (CASC.md §8.4) whose base or operand is not known until resolution --+hosts = ${EXTRA_HOSTS[]}, or an append to a list that is itself a reference. Applied once both sides resolve.