I am reading and taking notes on the HTML specifications for 100 days as part of #The100DayProject. Read the initial intent/backstory. I am a Microsoft employee but all opinions, comments, etc on this site are my own. I do not speak on behalf of my employer, and thus no comments should be taken as representative of Microsoft's official opinion of the spec. Subsections not listed below were read without comment.
Currently reading in 3.2.5 Global Attributes
188.8.131.52 The translate attribute
The translate attribute defines whether or not to translate the element's text when the page is localized. Values are easy: “yes” or “no”. If not set, the element inherits this attribute.
What this attribute’s value does in practice is set a translation mode on the element (“no-translate” or “translate-enabled”). If the element doesn’t have the attribute set, it also inherits translation mode. If the element is the root element, its translation mode is “translate-enabled”.
There is a list of an element’s attributes that can and should be translated, if the translate attribute was set to “yes”. Good to know it’s not just the text contents of the element; this is actually something I was wondering the other day, for practical application on a project.