"The purpose of this TSB is to provide generic guidelines for users and consumers of ""industry standard"" optical connectors as defined by the TIA-604-XXX series of Fiber Optic Intermateability Connector Interface Standards (FOCIS) documents. This document is meant to supply guidance to end-users as to how to specify and verify that terminated products complying to a particular FOCIS standard will perform as expected regardless of: Manufacturer of the unterminated connectors Supplier of the terminated assemblies Different operators within the same supplier The underlying issue is that specifying optical performance requirements is not enough. Without also specifying end-face profiles@ the user can be faced with a product that passed specified insertion loss eturn loss requirements against a test standard but performs quite differently when mated against other terminations. In addition@ defining and requiring that the end-face profile be within some range is important for interconnect reliability. Various types of end-face profiles and recommended values for the most popular ferrule/fiber configurations are provided in this TSB. The values provided in this document are derived from various resources@ including the Telecommunications Industry Association@ Telcordia@ NASA@ and various connector manufactures. For particular application and/or particular combination of fiber/cable/connector combination@ the user is directed to determine if other values or criteria are more appropriate. In their absence@ the default values would serve the requirements of most commercial applications."