Hi, After the changes mentioned in previous announcements    , the valid MathML length values are almost a subset of CSS <lengths-percentage> and we could consider relying on the CSS parser in the future.
The only remaining difference is in the definition of numbers since MathML3 allows the following case: an optional "-", followed by a nonempty sequence of digits, followed by a dot. For example "42.px" is valid MathML3 length and equivalent to "42px". For details see . The MathML CG decided to align the definition of numbers on CSS . This syntax is supported in WebKit too. However, it seems safe to unship it without deprecation warning since it's really an edge case and it is very unlikely that people/tools would write/generate a number ending with a dot. I plan to do this in bug 1575596.  https://groups.google.com/forum/#!topic/mozilla.dev.platform/yEMdIOo4i-0  https://groups.google.com/forum/#!topic/mozilla.dev.platform/kyB34PjYXek  https://groups.google.com/forum/#!topic/mozilla.dev.platform/G91-vBeC3Rw  https://groups.google.com/forum/#!topic/mozilla.dev.platform/-yV6wb3klSA  https://bugzilla.mozilla.org/show_bug.cgi?id=1574751#c2  https://github.com/mathml-refresh/mathml/issues/23 -- Frédéric Wang _______________________________________________ dev-platform mailing list email@example.com https://lists.mozilla.org/listinfo/dev-platform