Q: How do I select baselines between EVLA-VLA antennas in CASA (e.g. to flag them, keeping the EVLA-EVLA and VLA-VLA only)?

A: The solution in CASA is to use wildcards "*" in the antnenna selection string. If you've used the new antenna name convention in filling the data (in importvla or importuvfits), you can use antenna = 'ea*&va*' (for data from importvla) or antenna='EA*&VA*' (for data from importuvfits). If you've got the EVLA vs VLA in the station names, you can use something like antenna='EVLA:*&VLA:*' (as the selection searches stations after checking names).