"Register true" Layout property for page styles

On the LO user's mailing list, someone was asking how to line up paragraphs of mirrored pages. Regina mentioned this as a way to do this.
      This is the first time I have heard about it. (Maybe I have not read the Writer Guide close enough.)
      Should we be using this property in our documentation? I notice that it is not selected in the chapter template. Is this something to consider when updating the template?

--Dan

The typographical term for employing that is registration (LO uses register-true, selected on/off by toggling a check box). The online help covers that.

Gary