PRE 14C All preliminary information statements, excluding, mergers, contested solicitations and special meetings.
DEF 14C All types of definitive statements, excluding: mergers or acquisitions, contested solicitations and special meetings.
Reg D Companies selling securities in reliance on a Regulation D exemption or a Section 4(6) exemption from the registration provisions of the '33 Act must file a Form D as notice of such a sale. The form must be filed no later than 15 days after the first sale. The exact form type is usually REGDEX, but may be a REG D-1 or similar.
SB-2 This form may be used by "small business issuers" to register securities to be sold for cash.
S-8 This form is used for the registration of securities to be offered to an issuer's employees pursuant to certain plans.
S-1 This is the basic registration form. It can be used to register securities for which no other form is authorized or prescribed, except securities of foreign governments or political sub-divisions thereof.
1-E / 2-E Business development companies (BDC) can avail themselves of a more esoteric provision of the Securities Act – Regulation E, which provides an exemption from registration for securities issued by BDCs. In short, under Regulation E, a BDC may issue up to $5 million worth of securities a year without registration. Also under Regulation E, an individual may offer to sell up to $100,000 of securities in a BDC each year.
424B1 and 424B3 filings are final registration statements to register stock under previously filed SB-2 S-1 and S-2 filings, and they serve other purposes, I think. (I haven't seen this in that exact wording, but it appears that way to me, having seen so many. I.E. The SB-2's and S-1 and S-2's appear not to be effective until the corresponding 424B filing is registered.) First please see this post: http://www.investorshub.com/boards/read_msg.asp?message_id=9119580