> In a style file would say TeX barf if it contained utf-8 characters even if > I have them in a conditional sothat the are not processed by the engine > just parsed?
I believe that it would be ok if you use the actual bytes ^^c3 and ^^b5 in the file. The reason is that pdfTeX only makes (most) code points from 0 to 31 invalid (?), and those only appear in the utf-8 encoding of the Unicode code points 0 to 31, which you are probably not using in your files (except 9, 10, 13, which are ok for pdfTeX). On the other hand, if you want to use the ^^ notation, for pdfTeX (set up with the appropriate inputenc option) you'd need to use the eight characters ^, ^, c, 3, ^, ^, b, and 5 (that'd give you à and µ in [Xe/Lua]TeX), whereas for the other two engines you'd need either ^^b5 or ^^^^00b5. In this last case of the ^^^^ notation, pdfTeX will choke even if it appears in the unused branch of a conditional. Now, why would anyone use the ^^ notation? Because it is most robust against encoding changes since we then only use ASCII characters. Using utf-8 encoded characters directly is only good if you stick with utf-8 (which I'd advise). So I'd say my impression is that the best is to use ^^^^xxxx, but in a separate file, loaded for the luatex or xetex engine. Three other options: * Keep one file, work in a group, and use \catcode`\^^^=9 for the pdftex engine before any ^^^^xxxx appears. * Put the pdfTeX-specific commands first in the file, and conditionally \ifpdftex \endinput \fi, then anyhing can appear later in the file. * Use \char"00b5, which only works if your font is encoded in a sensible way IIRC. Hope that helps (and is correct), Bruno -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex