For issue #42, made the following changes to dialog_modal section of aria-practices.html: 1. Minor editorial revisions to the introduction for clarity. 2. Made reference to nonmodal dialogs a link to ...

Modal dialogs should follow accessibility patterns to ensure they are perceivable, operable, and understandable for all users. The role="dialog" attribute should be used to indicate the overlay is ...

Our experience has been that most dialogs are modal, as in the example you provide in Dialog (Modal). However, the pattern contains the following passage: Like non-modal dialogs, modal dialogs contain ...