A method for setting up a group call within a dispatch radio communication system is disclosed. Additional stations which are not programmed to respond to a transmitted group identification code (GIC) are enabled to join the call. The method comprises steps carried out by a service provider of (a) providing first and second additional fields in a set-up message, the first additional field carrying a Group Call Access Permission (GCAP) value and the second additional field carrying a Help Request Level (HRL) value, (b) enabling a call initiator to select a GCAP value, according to a range of stations the call initiator wishes to reach, and a HRL value, according to an assigned call priority, for transmission alongside the GIC in the step (a) fields, and (c) enabling any station that receives a set-up message to determine whether to join the call based on the GCAP and HRL values.