This paper analyses three existing tagsets for dialogue acts, i.e., the function of utterances in dialogue. Then, a new tagset is proposed, named MALTUS, designed for the annotation of meeting recording transcripts. Several criteria for tagset definition are discussed, along with the possible theoretical inspiration for dialogue act tagsets. The DAMSL, SWBD-DAMSL, and ICSI-MR tagsets are analyzed with respect to the previous considerations. The definition of MALTUS is followed by quantitative data from the conversion and validation of ICSI-MR data, and then by perspectives on automatic tagging using MALTUS, and on further user-based studies of its relevance.