17 CFR § 232.305 - Number of characters per line; tabular and columnar information.
(a) The narrative portion of a document shall not exceed 80 characters per line, including blank spaces, and shall not be presented in multi-column newspaper format. Non-narrative information (e.g., financial statements) may be presented in tabular or columnar format and may exceed 80 positions only if it is tagged as specified in the EDGAR Filer Manual. In no event shall information presented in tabular or columnar format exceed 132 positions wide.
(b) Paragraph (a) of this section does not apply to HTML documents, Interactive Data Files (§ 232.11) or Interactive Data Financial Reports (§ 232.11).