I've been looking at a number of fares in Basic Economy, both fully domestic (within the US) and Canada-US. At the purchase stage,
United has a pop up [see below] requiring actual acknowledgement of the BE limitations, but
strongly suggests that a full-size carry on is permitted on board.
This flies completely in the face of the limitations described in the Basic Economy section
here, where a plain reading suggests that a full-size carry on is not permitted on board for BE tickets, at any price (in fact, they are to be checked at the gate at the checked bag fee + $25).
Now, based on the below, I would suggest that UA's representations are sufficiently unclear as to confuse even a sophisticated purchaser of travel. To be clear, we are not talking about Transatlantic or Transpacific international itineraries.
What say the UA experts of the forum (both based on this graphic, as I explained it, and their personal experience)?
Print screen