Hi. You need to understand that those meta keywords used to have influence on forming search results.
There is though some basic meta keyword rules:
- up to 20 maximum keywords in meta tag
- up to 250 characters total
- no more than 3 repeats of 1 keyword.
You can recount them with a comma or just space - there is no right answer.
You can also add some typos of keywords if there is some popular in your case.
Now, as I wrote before - "used to have influence". Not anymore, because Google and Bing both do NOT care now about meta-tag "keywords" when ranking pages.