# Is a charged-coupled-devices tag okay? If so, what would be good usage guidance for it?

I've just added the new tag to How often are electron-multiplying CCDs used in telescope focal planes? Will Nancy Grace Roman be the first use in a space telescope? since that's the primary target of the question. I think we've had several questions before that are primarily about how CCDs work and how they are operated in astrophotography situations.

I did not add it to its companion question Why does Nancy Grace Roman = 100 × Hubble? Why is the new space telescopes wide field camera so much wider than the old one's? because while it involves what's at the focal plane, it's not specifically about the design and operation of charged-coupled devices.

We don't have a focal-plane or instrumentation tag, and seems to general and more about a larger assembly than a CCD and its associated electronics.

Shall we keep this tag? If so, what would good usage guidance for it be?

+3/-0 votes on the question so far and no negative comments; it seems like the tag is okay.

The only problem with the tag as-is is that it doesn't appear when you search for "CCD" :-)

Also, would a future "CMOS" tag be appropriate, or would an all-encompassing "imaging devices" or "photon sensors" tag be better?

• Thanks for your answer! I know what you mean about CCD and I had thought about using that instead, it's not too late to switch to that, charge-coupled-devices only has two questions. In FAQ we can find What are tag synonyms and merged tags? How do they work? and it seems to me that both tags must exist and be used first before any synonymization can occur, but I'm no expert. – uhoh Feb 6 at 13:48
• So for now I think we should choose whichever one is most likely to be typed by someone hunting for such a tag. That's why I wouldn't suggest "imaging devices" or "photon sensor" or "CMOS" as a main tag; I thing fewer people will start typing those and looking for the auto-complete. – uhoh Feb 6 at 13:50