# Is creating a unit a 'user' function?

Working on `siunitx` version 2, I’m confronted with a slight problem. Currently, the macros used to manipulate units are called

• `\newunit`
• `\renewunit`
• `\provideunit`

which follows the LaTeX 2e `\newcommand`, etc.; the same is true for prefixes and so forth. These names were probably not the best choice: for example, `biblatex` also has a `\newunit` macro (although there is not a clash, luckily).

I’ve been thinking of better names, but I’m not sure whether these should be document level (all lower-case), or design level (mixed upper-case and lower-case). Some ideas:

1. `\DeclarePhysicalUnit` (create without checks)
2. `\NewPhysicalUnit` (create with checks: would require `\RenewPhysicalUnit`, etc.)
3. `\NewUnit` (as 2 but shorter)
4. `\newphysicalunit` (as 2 but document level)
5. `\createphysicalunit` (is ‘create’ better than ‘new’?)
6. `\createunit` (avoids the confusion with `biblatex`)

You’ll see that I’ve not included ‘SI’ in any of the above: it looks odd, and of course you can create non-SI units anyway. How do other people see this?