Real support exists but it does not close the question. In practice this is one of three situations: a single source with nothing corroborating it, a figure the interested party reported about itself, or a result too recent for anyone else to have tested. Usable, but say where it came from when you repeat it.
The definition the product enforces, read from the same code the methodology page renders.
Read the source line before leaning on it. A partial grade usually means one of three things: a single source, a figure the interested party reported about itself, or a result too new to have been tested. Quote it with its origin attached.
The grade every claim on a research page carries: how it is known, not how confident it sounds. Assigned by the same rules on every scan; the rollup numbers are computed from the graded rows.
Every grade here is assigned by the same rules on every scan, and the methodology page renders those rules from the code that enforces them.