RdTextFilter(ifile, encoding = "unknown", keepSpacing = TRUE, drop = character(), keep = character(), macros = file.path(R.home("share"), "Rd", "macros", "system.Rd"))"Rd" object
  from parse_Rd.
parse_Rd.
parse_Rd.
"TEXT" are kept in the same position as
  they appeared in the original file, while other parts of the file are
  replaced with blanks, so a spell checker such as aspell
  can check only the text and report the position in the original file.
  (If keepSpacing is FALSE, blank filling will not occur,
  and text will not be output in its original location.)  By default, the tags \S3method, \S4method,
  \command, \docType, \email, \encoding,
  \file, \keyword, \link, \linkS4class,
  \method, \pkg, and \var are skipped.  Additional
  tags can be skipped by listing them in the drop argument;
  listing tags in the keep argument will stop them from being
  skipped.  It is also possible to keep any of the
  c("RCODE", "COMMENT", "VERB") tags, which correspond to R-like
  code, comments, and verbatim text respectively, or to drop
  "TEXT".
aspell, for which this is an acceptable filter.