ParallelDOM.js uses at least 8 different names for "primary sibling"

[pixelzoom]

In ParallelDOM.js, there's a nice description of "primary sibling":

The api in this trait allows you to add additional structure to the accessible DOM content if necessary. Each node
 * can have multiple DOM Elements associated with it. A Node can have a label DOM element, and a description DOM element.
 * These are called siblings. The Node's direct DOM element (the DOM element you create with the `tagName` option)
 * is called the "primary sibling." You can also have a container parent DOM element that surrounds all of these

Good definition, nice simple concise term.

Then ParallelDOM.js uses no less than 8 other names for "primary sibling":

primary sibling DOM element
primary element
primary DOM element
primary dom element
primary sibling element
primary sibling in the PDOM
primary sibling DOM Element
primary sibling of the PDOMPeers

Are these indeed all the same things?
Can "primary sibling" be used everywhere, to make this less confusing?

[zepumph]

Perhaps related to #1298