7553691c_Product_Accessibility_Template_tion_and_Applications___Detail_Remarks_and_explanations
[Criteria] (a) A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content). [Supporting Features] Supports with Exceptions [Remarks and explanations] 
Authors can add textual alternatives to their images, but some automatically generated content, such as the Document Type icon, do not include text alternatives.
Adobe LiveCycle Mobile Forms ES4 Voluntary Product Accessibility Template