The present disclosure relates to the field of holding frames for a plug connector for receiving similar and/or different modules. To provide a solution which retains the flexibility in the number of insertable modules which previously resulted from being able to select a matching holding frame, while allowing a more efficient layout, manufacturing, storage and/or use, an appropriate holding frame arrangement is proposed in which the modules in a holding frame arrangement to be populated with modules are arranged one beside the other in a longitudinal direction thereof, between a first and a second end face of the holding frame arrangement, wherein the first and the second end faces are configured to be joined to each other form-fittingly such that, in a populating state, at least one transversely extending projection of one of the modules is received in a receptacle in at least one of opposing side surfaces of the holding frame arrangement, which extend between the first and the second end faces.