The CDSUTILS package has a feature where it substitutes in a C1 or H1 or L1 prefix depending upon what site you are at. The idea is that this should make code portable between LLO and LHO.
Here at the 40m, we have no need to do that, so its better for us to be able to copy and paste channel names directly from MEDM or whatever without having to remove the "C1:" from all over the place.
the way to do this on the command line is (in bash) to type:
To make this easier on us, I have implemented this in our shared .bashrc so that its always the case. This might break some scripts which have been adapted to use the weird CDSUTILS convention, so beware and fix appropriately.