Vignette: 'CRAN_mirror' -> CRAN'?

[HenrikBengtsson]

The vignette mentions CRAN_mirror;

https://github.com/Bioconductor/BiocManager/blob/ce4586155ec7f59bffb6d040321bb569713ce2ac/vignettes/BiocManager.Rmd#L284-L287

Is that CRAN_mirror meant to be CRAN that R recognizes?

FWIW, contrary to BioC_manager, CRAN_mirror is not something R itself is aware of. I searched the BiocManager source code for CRAN_mirror in case it make use of it internally, but couldn't find anything.