Hi Bjarne
Don't know if any international standards for abbreviations or shorthand notation of material description or analysis exist.
With all abbreviations or shorthand notation, it is important that your reader/audience understand. Its a bit like the term HVOF or PVD, which is fine for people that know what your talking about, but for those that don't, it should be expressed properly "High Velocity Oxygen Fuel" or "Physical Vapour Deposition".
With shorthand notation for material make-up, I think it is important to differentiate between alloy/compound and composite/blend. With a nickel chromium boron silicon alloy, I feel NiCrBSi is better than Ni-Cr-B-Si as the hyphens tend to indicate separation as in a blend or composite. Usually, expressing content in descending order (main constituent first) Composites expressed as WC/CoCr or WC-CoCr (tungsten carbide in a cobalt chromium alloy matrix) I think is OK, but WCCoCr would be quite different. If we need to be a little more precise with composition, it is usual to preceed the element or compound symbol with a number to represent % by weight (confusion could arise from %mol or %vol so these should be specified if different) like WC/10Cr4Cr or 86WC-10Co4Cr. Two powder types common in thermal spray contain nickel and ~5% aluminium. The alloy version I would express as NiAl or Ni5Al, the composite version as Ni/Al or Ni-Al or Ni/5Al or Ni-5Al.
It would be nice to have some form of internationally recognised standard (should they not already exist) like we have for element and compound symbols, but how long have SI units been about, and how many of us still use inch, foot, pounds, imperial gallon and us gallon?

We all need to speak the same language but whose is best