Comparative and superlatives are not comparable each other, so LOWER RATING and UPPER RATING dos not mean it is lower or upper than a medum rating. I would not accept these two meaningless names that are too much confusive, unless they are used to denote NOT absulte ratings but comparative ratings only (in which case there's only 3 levels: LOWER, SAME and UPPER; or NEGATIVE, NULL and POSTIVE for the differences of absolute ratings).
For now we only have some WHITE and BLACK characters, for noting a binary value (without saying which one is positive/true and which one is negative/false), it does not encode either the absence of data (N/A), meaning that it is not really binary but only dual, without any numeric value associatable). But for everything else about absolute ratings, it's illusory to start encoding more numeric values : how many will be needed and used is endless along at least two orthogonal axis of expansion : the choice of the base character, and the number of values needed (plus their scale, i.e. their minimum relative numeric difference, and the origin for counting, i.e. zero or one). If something gets encoded we should not associate a specific scale, and in fact it would be highly preferable to use a normalized scale (e.g. in percents), to preserve the flexibility of use with arbitrary scales: this has been made for a few gray-filled BOX symbols (initially used in old text-only terminals and old standards like IBM PC character sets for text mode, and similar symbols of various terminals and older computers working with monospaced fonts only).
