Minimum Crossing Altitude

A MCA (Minimum Crossing Altitude) is the lowest altitude at certain fixes at which the aircraft must cross when proceeding in the direction of a higher minimum en route IFR altitude.

The symbol looks like a flag with an “X” in the middle, here’s an example.

References:
1. “Page 665” of the Pilot/Glossary in the AIM

September 10, 2019 by Kyle Boas