Current PSTN/Internet Interfaces (PINT) WG addresses connection arrangements through which Internet applications can request and enrich PSTN (Public Switched Telephone Network) telephony services. Some Interworking services require Notification and requests for services that come from PSTN/IN. Essentially, these requests will be "mirror image" of PINT requests. To provide interoperability between PSTN and IP networks, it  is very important to ensure notification to the IP network of  the events happening in PSTN. PSTN/IN Call Flow is organized around actions or collections of actions called Point-In-Call (PIC). Detection Points (DPs), which are associated with the PICs, operate between the PICs and can be the basis for Notification Events for Interworking with IP network. IN furnishes "Network Intelligence" to PSTN. Similarly, it can be utilized to initiate Notification Events to IP network. We are proposing new Working Group to be a "mirror image" of the PINT WG, regarding direction of the requests for service and dealing with  Notification only. Like PINT, PIN will not deal with IP Telephony,  but  rather  provide requests for services and Notifications from PSTN/IN to IP network in order to augment, extend and enrich PSTN. PIN WG would focus on the PIN Protocol Requirements and Definition of Notification Processing Language (NPL) - a possible extension to CPL, as well as defining connections of Services to the IN DPs. PIN protocol is a specialized protocol used for communication between the  PIN Gateway and PIN Servers, which may, potentially, be used for communications between PIN Servers and PIN Clients. NPL will allow to build new Notification Services and provide means to describe Notification Filters to screen PSTN events. Notification Filter  example: Notification for an Attempt to Enter Conference from a predefined number in the hours 9 through 17 only on weekends and holidays. It is quite possible that existing or under development protocols (i.e. SIP, PIP, MGCP, etc.) are sufficient to support PIN Services, but that determination is for further study by the PIN WG.