Identifiers are 32-bit integers with their three most significant bits equal to zero. Every client has its own set of identifiers it can use for creating new resources. This set is specified by the server as two integers included in the acceptance packet (the packet it sends to the client to inform it that the connection is accepted). Clients choose identifiers that are in this set in such a way they do not clash: two objects among windows, pixmaps, fonts, colormaps, and graphic contexts cannot have the same identifier.