RMarkdown comes with excellent spell check support, which is based on the Hunspell engine.
There is also a nice short blog about it on https://support.rstudio.com/hc/en-us/articles/200551916-Spelling-Dictionaries.
When working on multiple computers (or having multiple users work on 1 project), it can be nice to synchronize dictionaries across computers to avoid repeatedly adding specific terms like "homoscedasticity" to the dictionary.
Therefore, it would be useful to know the path of the default dictionary used by RStudio. It could then be simply added under version control of a project.
How about using a custom dictionary for your project (as described in the RStudio blog post you linked) that you keep under version control? It’s not very hard to make a Hunspell .dic file — at its simplest, it’s just a UTF-8 text file with one word on each line.
Btw, the Hunspell integration is provided by the RStudio IDE, not the RMarkdown package, so you might want to recategorize your post so it reaches the most relevant audience.
Thanks a lot for your help. This is certainly a simple and good way.
Especially the URL to hunspell was very helpful, because it convinced me, that the word list is as simple as it can be and requires no magical syntax.
I think there's one caveat to it: When I add a new word to the dictionary, it will get added to the default dictionary and not the custom one. So one would need to add it there, too. This works but is not the most elegant solution I can think of.