Now when Forum supports the aggregate type "Count of ratings", it would be useful to allow one-item scales. The same improvement has been recently implemented at moodle.org - Using Moodle forums can be rated by a single-item scale "Useful post".

Currently, the standard distribution od Moodle does not allow you to create scales with just one item. This is a proposal to allow such scales. If there are no regressions, I propose to consider this as a bug and introduce it on MOODLE_19_STABLE. Or, at least, publish a patch allowing this on users' own risk.