I found
here this text which could explain why
all is not considered to be adequate. Maybe I could try
screen. But I will ask the question.
Media dependencies
HTML allows authors to specify documents in a media-independent way. This allows users to access Web pages using a wide variety of devices and media, e.g., graphical displays for computers running Windows, Macintosh OS, and X11, devices for television sets, specially adapted phones and PDA-based portable devices, speech-based browsers, and braille-based tactile devices.
Style sheets, by contrast, apply to specific media or media groups. A style sheet intended for screen use may be applicable when printing, but is of little use for speech-based browsers. This specification allows you to define the broad categories of media a given style sheet is applicable to. This allows user agents to avoid retrieving inappropriate style sheets. Style sheet languages may include features for describing media dependencies within the same style sheet.
But here, they say
all could be OK for stylesheets
http://www.w3.org/TR/html40/types.ht...ia-descriptors
Taking into account Jellby proposal, when suppressing
media="all", FlightCrew seems to feel happy and reports no more mistake.
But if I change
"all" by "
screen", he still reports the same mistake.
You're right. Could be a bug.Now issue 887.