2.2.17 [W3C-HTML52] Section 4.7.10. The video element

C0027: Screensavers are not disabled for fullscreen videos

The specification states:

 ... The video element
     ...
     User agents may allow video playback to affect system features that could interfere 
     with the user's experience; for example, user agents could disable screensavers while 
     video playback is in progress.

EdgeHTML Mode

Screensavers are not disabled for fullscreen videos.

C0024: No external link is provided if the video cannot be rendered

The specification states:

 ... The video element
     ...
     User agents that cannot render the video may instead make the element represent a 
     link to an external video playback utility or to the video data itself.

EdgeHTML Mode

No external link is provided if the video cannot be rendered.

C0025: Videos can be played fullscreen

The specification states:

 4.7.6 The video element
     ...
     User agents may allow users to view the video content in manners more suitable to the 
     user (e.g. fullscreen or in an independent resizable window). ...

EdgeHTML Mode

Videos can be played fullscreen.

C0023: Visual indicators provide the state of the video

The specification states:

 ... The video element
     ...
     In addition to the above, the user agent may provide messages to the user (such as 
     "buffering", "no video loaded", "error", or more detailed information) by overlaying 
     text or icons on the video or other areas of the element's playback area, or in 
     another appropriate manner.

EdgeHTML Mode

Visual indicators provide the state of the video.

C0026: Fullscreen videos show controls and ignore the controls attribute

The specification states:

 ... The video element
     ...
     ... In such an independent context, however, user agents may make full user 
     interfaces visible ... even if the controls attribute is absent.

EdgeHTML Mode

Fullscreen videos show controls and ignore the controls attribute.