base_formatargument has been removed from
copernicus_article()(#172). This argument was originally added mainly for supporting
bookdown::pdf_book(), but you should really pass these formats to the
bookdown::pdf_bookinstead of the other way around. See https://bookdown.org/yihui/rmarkdown/rticles-bookdown.html.
For output formats
mnras_article(), the csl file should be specified as a top-level option in the YAML header of the document (this has been done in the R Markdown templates). It is no longer specified automatically by the output format functions.
ctex_template()was removed. If you need to use a custom LaTeX template for the
ctexoutput format, just use the