Neil Saunders shows how you can parameterize Rmarkdown files, consequently making changes easy later:
The reports follow a common template where the major difference is simply the hashtag. So one way to create these reports is to use the previous one, edit to find/replace the old hashtag with the new one, and save a new file.
That works…but what if we could define the hashtag once, then reuse it programmatically anywhere in the document? Enter Rmarkdown parameters.
The example is small but important.