warn about soh and log in water current section of fdsnIdentifiers

[crotwell]

I thought I had posted this before, but can't find it, so sorry if a repeat.

In the Water Current section of the FDSNIdentifiers document, add

Do not use SOH or LOG as these conflict with widely used state of health and logging channel identifiers.

[krischer]

This is already written in the beginning of section 3.

[crotwell]

Right, but because this is a special exception to this specific instrument, and the only case in which an instrument does not determine its acceptable band/gain codes, I feel it would be best to add it directly to the water current section.

[chad-earthscope]

Got it, add and additional note about the special exceptions of LOG and SOH to the "O" instrument where they would potentially collide. 👍