A mobile terminal 1 is attached to a first network 2 of a first technology type RAT1. The mobile terminal 1 transmits UE capability information to the first network 2 by a plurality of containers. Each container relates to one type of technology which is supported by the mobile terminal. Each container includes an indicator tag identifying the RAT to which its contents relate. On receipt of the containers, the first network 2 only decodes the content of the container that is indicated to be of its own technology type. If there is a neighbouring network 6 of another technology type with which the mobile terminal is compatible, the first network 2 send the relevant container to the second network, where its content is decoded. The second network may return generalized information derived from the container back to the first network. This mechanism provides a content-agnostic approach for transferring mobile capability information between networks of different technology types.