If you call @DbLookup with a list of keys, the lookup will stop after the first non-matching key. I would like it to keep going and process the rest of the keys in the list.
For example, say you want the entries for the months February, March, August and September, but August happens to have no entries. If you try to do this using a single @DbLookup (e.g. with the key field set to "February":"March":"August":"September"), the call will succeed but the entries for September won't be retrieved.
Assuming you even notice the problem, unless you have a way of knowing in advance which months have no entries, your only recourse is to make a separate @DbLookup for each month instead. Adding a keyword would also help to clarify the documentation, which doesn't make the current behavior clear.