In Quillen's original text on model categories (homotopical algebra) he uses $Q$ and $R$ to denote cofibrant and fibrant replacement respectively.

This notation has been used by several other authors including Hovey in Model Categories and Dwyer and Spalinski in Homotopy Theories and model categories.

Personally I find this notation confusing, especially when taking derived functors and having to work with the derived functor of fibrant replacement - usually denoted $RR$ - hence the confusion sometimes appears.

I have seen other authors use $\hat{c}$ and $\hat{f}$ for cofibrant and fibrant replacement respectively, which personally I prefer. This notation runs into problems if you take the fibrant replacement of a map $f$ - obtains $\hat{f}f$.

So my question is,

is there a "standard" notation for cofibrant and fibrant replacement that everyone can agree on, and that has minimal ambiguity?