Documentation for special values of key in each template helper

Hello! I'm not sure if this is the right place for this but I wasn't sure where to ask. In the current documentation for the each template helper it talks about specifying keys but makes no mention of the special values for key, namely:

@index - The index of the item in the array. @item - The item in the array itself. This can only be used for arrays of strings or numbers. @guid - Generate a unique identifier for each object (uses Ember.guidFor).

Which I discovered in this comment

Are these special values actually still valid in 3.2? And if they are, is it alright if I write them back into the documentation?