Proficiency can be shown by taking part in a suitable proficiency testing scheme (ISO/IEC 17043) run by an independent third party, which gives every team the same samples, predicts the expected results and compares each team's results with the prediction and with the other teams'; teams producing equivalent results are equally proficient in those analyses, though their report conclusions may still differ. Tests are repeated regularly to show proficiency is kept. Where no suitable independent test exists, a team may set up a scheme directly with other teams to suit its needs, ideally with independent scrutiny of the scheme.
This control maps to 2 controls across 2 other frameworks. If you already hold one of them, the evidence you collected for it is the starting point here rather than new work.
Every mapping shown was judged rather than inferred from wording similarity, and the ones that failed review are published too. See the coverage reports and what was rejected.
The graph holds this control, the 2 it maps to, and the evidence behind each claim, over MCP and REST.