This is the standard Microsoft term for functions that help handicapped people use their programs. The term is also frequently used by others and gives appr 1 millon Google-hits.

"Open XML formats are also distinguished by their approach to accessibility support for disabled workers, file performance and flexibility to empower organizations to access and integrate their own XML data with the documents they use every day. In contrast, ODF focuses on more limited requirements, is architected very differently and is now under review in OASIS subcommittees to fill key gaps such as spreadsheet formulas, macro support and support for accessibility options. As a result, certain compromises and customer disclosures will be a necessary part of translating between the two formats."