The USPTO is proposing limiting documents that may be sent via fax and specifying a minimum font size.  The release in the Federal Register said, in part:

The primary impact of the changes proposed in this notice are that: (1) Certain documents may no longer be submitted to the Office via facsimile transmission; and (2) certain documents submitted to the Office must have a minimum font size, namely a font that has capital letters no smaller than 0.28 cm (0.11 inch) high (e.g., a font size of 12 point in Verdana). The elimination of the availability of facsimile transmission will not have a significant economic impact because these documents may be submitted to the Office via EFS-Web or via the USPS by first class mail. The requirement that documents submitted to the Office must have a minimum font size will not have a significant economic impact because the current rules of practice require that such documents be ‘‘[p]resented in a form having sufficient clarity and contrast between the paper and the writing thereon to permit the direct reproduction of readily legible copies in any number by use of photographic, electrostatic, photo-offset, and microfilming processes and electronic capture by use of digital imaging and optical character recognition’’ (37 CFR 1.52(a)(1)(v)), and set forth that font size below the proposed minimum font size generally does not comply with this pre-existing requirement of the rules of practice. In addition, the overwhelming majority of the documents to which this provision applies are created using word processors, and it will not have a significant economic impact to change the font size on a word processor. Therefore, the changes proposed in this notice will not have a significant economic impact on a substantial number of small entities.

For the full text, see http://www.uspto.gov/web/offices/com/sol/notices/73fr45662.pdf.