M usually stand for metal. Are you getting these package types from a design or from a vendor? If your getting them from the vendor, get their datasheets, I'm sure there is some IPC equiv. Michael Kuczynski Librarian/Sr. Designer L3 Communications 1-201-393-2122 (Ph) Space & Navigation 1-201-393-6681 (Fax) 699 Rt. 46 E Mail Stop PL1/J8 Teterboro,NJ 07680 [log in to unmask] --------------------------------------------------------------------------------- DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF DesignerCouncil. To set a vacation stop for delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------