Tweak 84799.

git-svn-id: https://svn.r-project.org/R/trunk@84804 00db46b3-68df-0310-9c12-caf00c1e9a41

src/library/base/man/regex.Rd

@@ -310,8 +310,10 @@
  without property \samp{xx} respectively. For a list of supported
  properties see the PCRE documentation, but for example \samp{Lu} is
  \sQuote{upper case letter} and \samp{Sc} is \sQuote{currency symbol}. Note
- that for some properties to work, one may have to start the pattern with
- \samp{(*UCP)} and accept a performance penalty.
+ that properties such as \samp{\w}, \samp{\W}, \samp{\d}, \samp{\D}, \samp{\s},
+ \samp{\S}, \samp{\b} and \samp{\B} by default do not refer to full
+ Unicode, but one can override this by starting a pattern with \samp{(*UCP)}
+ (which comes with a performance penalty).
  (This support depends on the PCRE library being compiled with
  \sQuote{Unicode property support} which can be checked \emph{via}
  \code{\link{pcre_config}}. PCRE2 when compiled with Unicode support always