Reordering of bidirectional text into the @dfn{visual} order happens
at display time. As result, character positions no longer increase
monotonically with their positions on display. Emacs implements the
-Unicode Bidirectional Algorithm described in the Unicode Standard
-Annex #9, for reordering of bidirectional text for display.
+Unicode Bidirectional Algorithm (UBA) described in the Unicode
+Standard Annex #9, for reordering of bidirectional text for display.
+It deviates from the UBA only in how continuation lines are displayed
+when text direction is opposite to the base paragraph direction,
+e.g. when a long line of English text appears in a right-to-left
+paragraph.
@vindex bidi-display-reordering
The buffer-local variable @code{bidi-display-reordering} controls
which is described in Annex #9 of the Unicode standard
(@url{http://www.unicode.org/reports/tr9/}). Emacs provides a ``Full
Bidirectionality'' class implementation of the @acronym{UBA},
-consistent with the requirements of the Unicode Standard v8.0.
+consistent with the requirements of the Unicode Standard v9.0. Note,
+however, that the way Emacs displays continuation lines when text
+direction is opposite to the base paragraph direction deviates from
+the UBA, which requires to perform line wrapping before reordering
+text for display.
@defvar bidi-display-reordering
If the value of this buffer-local variable is non-@code{nil} (the