I'm asking with a particular eye on the Rogue's level 11 feature, "Reliable Talent":
By 11th level, you have refined your chosen skills until they approach perfection. Whenever you make an ability check that lets you add your proficiency bonus, you can treat a d20 roll of 9 or lower as a 10.
The obvious application is to skills/tools you are proficient in. However, the wording doesn't mention proficiencies specifically. Does anything other than proficiency allow you to add your proficiency bonus to an ability check?
The Bard's "Jack of all Trades" feature allows you to add half of your proficiency bonus. Not enough to trigger Reliable Talent, however. (Possible follow-up question: If something else also gave half of your proficiency bonus to the check, would you then trigger Reliable Talent? Is there anything else that gives you half of your proficiency bonus?)