Markus Scherer wrote: > If software claims that it does not modify the contents of a > document *except* for initial U+FEFF > then it can do with initial U+FEFF what it wants. If the > whole discussion hinges on what is allowed > <em>if software claims to not modify text</em> then one need > not claim that so absolutely.
That seems pretty straightforward, but only as long as your "software" is an editor and your "document" is a single file. How about a case where "software" is a copy or cat command, and instead of a document you have several (plain?) text files that you concat? What does "initial" mean here? What happens next is: some software lets an initial BOM get through and appends such string to a file or a stream. If other software treats it as a character, the data has been modified. On the other hand, if we want to allow software to disregard BOMs in the middle of character streams then we have another set of security issues. And not removing is equally bad because of many consequences (in the end, we could end up with every character being preceded by a BOM). > .txt UTF-8 require We want plain text files to > have BOM to distinguish > from legacy codepage files Hmmmm, what does "plain" mean?! Perhaps files with a BOM should be called "text" files (or .txt files;) as opposed to "plain text" files, which in my opinion should be just that - _plain_ text. No ASCII plain text file had an ASCII signature. I believe "plain text" should be something that will be as easy to use (and handle) as ASCII plain text files were. True, UTF-16 files do need a signature. Well, we just need to abandon the idea that UTF-16 can be used for plain text files. Let's have plain text files in UTF-8. Look at it as the most universal code page. Plain text files never contained information about the code page, why would there be such information in UTF-8 plain text files?! How about this: * BOM makes a file stateful. * Plain text should NOT be stateful (or, we should make it as stateless as possible) * If a text file is stateful, it is no longer a "plain text file", it becomes a "text document". BTW, since I may be tempted to process text documents with plain text tools, I would rather see that the text documents would NOT have the BOM (yes, that effectively makes them plain text files). Since it seems that many people will insist that they want the option to have the BOM in text documents, it seems that it will need to be allowed. But I would not make it "required". Lars Kristan
