From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Index entry for Object Replacement Character Date: Tue, 05 Nov 2013 19:59:10 +0200 Message-ID: <83txfq7ms1.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1383674386 5978 80.91.229.3 (5 Nov 2013 17:59:46 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 5 Nov 2013 17:59:46 +0000 (UTC) Cc: emacs-devel@gnu.org To: Xue Fuqiao Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Nov 05 18:59:49 2013 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Vdkuo-0001s7-Th for ged-emacs-devel@m.gmane.org; Tue, 05 Nov 2013 18:59:47 +0100 Original-Received: from localhost ([::1]:57761 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vdkuo-00052w-LE for ged-emacs-devel@m.gmane.org; Tue, 05 Nov 2013 12:59:46 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:41045) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vdkue-00051F-QW for emacs-devel@gnu.org; Tue, 05 Nov 2013 12:59:44 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VdkuS-0001aj-Eq for emacs-devel@gnu.org; Tue, 05 Nov 2013 12:59:36 -0500 Original-Received: from mtaout20.012.net.il ([80.179.55.166]:57029) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VdkuS-0001aN-62 for emacs-devel@gnu.org; Tue, 05 Nov 2013 12:59:24 -0500 Original-Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0MVS00C00XW3PL00@a-mtaout20.012.net.il> for emacs-devel@gnu.org; Tue, 05 Nov 2013 19:59:11 +0200 (IST) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MVS00CAVXYNLM40@a-mtaout20.012.net.il>; Tue, 05 Nov 2013 19:59:11 +0200 (IST) X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 X-Received-From: 80.179.55.166 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:164969 Archived-At: I don't understand why you added an index entry for this. Can you explain? Here's my take on this: Index entries exist to make it easier for the reader to find the description/discussion of a subject. In this case, the subject of the text where the Object Replacement Character is reordering of display properties in bidirectional text. The fact that the Emacs implementation treats text covered by a display property as if it were a single character with the bidirectional properties of u+FFFC is an implementation detail, mentioned by the way for those who are interested enough to look up that character. The text does not explain anything about that character, and doesn't say why it was chosen for this role. The character is mentioned once, and that's it. Therefore, I find it hard to believe that any reader will thing about this character's name as a good string to try at the prompt of the Info's 'i' command. Likewise, I see no reason why someone who wants to know about this character will look for its description in the ELisp manual. So having this index entry there is not useful. More generally, not every term you see in a manual deserves an index entry. It only does deserve an entry if (a) the term is described and explained at that place, and (b) there's a high probability that readers will think about the phrase you put in an index entry when they are looking for the subject described at that place.