Edge id's consist of the element name prefixed with Stage_. Why is this not documented?

Suppose there is a symbol with a name of "mySymbol" with a text element named "text" within it.  To change the value of the “text” element, the documentation would have it done this way:

               sym.getSymbol("mySymbol").$("text").html('new world');

Using the “Stage_” notation, the text element can also be changed this way:

               $("#Stage_mySymbol_text").html('new world')

Note the underscore(_) between "Stage_mySymbol" and the text element. This creates a kind of “dot” notation. Instead a “dot” an underscore is used.  "Stage_mySymbol" represents the symbol "mySymbol" and "_text" the text element within it.

To me, conceptually, using "Stage_" is better and seems closer to jquery syntax.

Since this is not mentioned in the documentation, I am concerned that it might become deprecated.

Any ideas why the “Stage_” notation for id’s is not documented?

Is there a chance it will become deprecated?