Support for Unicode characters outside of the Base Multilingual Plane (BMP), i.e., characters whose code points are greater than 65535, is not yet implemented. See bug 51843. The writing-mode property does not produce the expected behavior when specified on fo:simple-page-master or fo:region-* elements. See bug 53276. Support for Devanagari and other Indic scripts is not yet complete. Use of Unicode U+200C ZERO WIDTH NON-JOINER (ZWNJ) or U+200D ZERO WIDTH JOINER (ZWJ) does not prevent or force contextual substitution, respectively, when used with Arabic script. Use of Unicode U+200C ZERO WIDTH NON-JOINER (ZWNJ) or U+200D ZERO WIDTH JOINER (ZWJ) does not affect conjunct formation or other special behavior prescribed when used with Indic scripts. Support for automatic line breaking at orthographic syllable segment boundaries in Indic or Southeast Asian scripts is not yet available. In the mean time, use U+200B ZERO WIDTH SPACE (ZWSP). Complex script content is presently supported only with AT, IF, and PDF output formats. When complex script text encounters an fo:inline or fo:character boundary, contextual substitution and ligature formation will not occur across the boundary. This prevents, for example, applying a different color to an Arabic Letter within an Arabic word, unless that letter is a non-joining letter (on both sides).