Grammar: Clippings

 

Clippings, or truncations, are shortened word forms. They are perfectly acceptable informally, but their suitability for formal English depends
on the rather subjective criterion of how 
well established they are.

The following, for example, should be spelt in full in formal English 

      ad (advertisement)
      demo (demonstration)      
      info (information)
      intro (introduction)

      pro (professional)

These are now formally acceptable and, in most circumstances, preferable to their full alternatives –

      bus (omnibus)
      cello (violoncello)     
      fax (facsimile)
      piano (pianoforte)
      vet (veterinary surgeon)

while opinion might differ on these 

      disco (discotheque)
      exam (examination)
      flu (influenza)
      fridge (refrigerator)
      lab (laboratory)
      phone (telephone)
      photo (photograph)

The practice of using apostrophes with clippings ('piano, lab') is obsolete.