The network switch in TCLN 1 is provided so that no attempt is made to calculate a network output if only the input parameters are required. The network may then be left undefined (ie no TCLN 2 bank). This situation will arise when the user is producing parameter sets of a known class of event for the purpose of training a network. The training can be performed with external software such as SNNS18.1. (A small fortran utility exists for converting ntuples to SNNS pattern files - contact Oxford). After training, the thresholds and weights can be put into the TCLN 2 titles bank. (Again, there is a utility for converting SNNS net files to the TCLN 2 bank format).