Do we want both proprietary-code and closed-source tags?

Question

Curiousdannii remarked in chat that we have both the tags proprietary-code and closed-source. Their use seems to be very similar. Should we have both, or can we merge them in to one?

An NGram search over google books shows that proprietary code or proprietary software are far more used than closed source.

edit: Maybe throw in proprietary for good measure. There are only two uses (of which one is non-software)

Answer 1

No, we don't need both. Make closed-source a synonym of proprietary-code

Answer 2

An alternative viewpoint, since I think "closed source" is more likely to be recognized than "proprietary code" - it's just more obvious:

No, we don't need both. Merge the two, and make proprietary-code a synonym of closed-source.