Some Form 990 software, used to prepare paper filings, transfers all narrative information that does not fit on the core form or schedules onto Schedule O. Other software permits this information to be reported, for paper filings, in separate statements or white paper attachments that are not a part of the Form 990. May either method be used when filing a paper Form 990? Only certain documents may be attached when filing the Form 990 (see Permitted and Impermissible Attachments). A reasonable cause explanation for a late-filed return must be made in a separate attachment, rather than in Schedule O, because such explanation would be publicly disclosed if included in Schedule O.