<p>I don't think type C questions should be tagged R.  Surely R tags should be for questions that require knowledge of R to answer - R is not a hard syntax, so for the examples above many non R users would understand and be able to answer the question.  I don't think syntax highlighting is important enough, and anyway most people put the output in as well, which always highlights wrong (e.g. the "Interpretation of R's lm() output" link above).</p>

<p>Type B questions I'm more unsure of.  On the one hand, they create an enormous number of R tags, but on the other hand they do need some R expertise.  If there are any answerers who follow the R feed because they have lots of R experience, then it is important these are tagged as R.  On balance I would say they should be tagged R.</p>
