Hopefully all System z users are aware of the Monthly Licence Charge (MLC) pricing mechanisms, where a recurring charge applies each month. This charge includes product usage rights and IBM product support. If only it was that simple! We then encounter the “Alphabet Soup” of acronyms, related to the various and arguably too numerous MLC pricing mechanism options. Some might say that 13 is an unlucky number and in this case, a System z pricing specialist would need to know and understand each of the 13 pricing mechanisms in depth, safeguarding the lowest software pricing for their organization! Perhaps we could apply the unlucky word to such a resource. In alphabetical order, the 13 MLC pricing options are AWLC, AEWLC, CMLC, EWLC, MWLC, MzNALC, PSLC, SALC, S/390 Usage Pricing, ULC, WLC, zELC and zNALC! These mechanisms are commercial considerations, but what about the technical perspective?