When you work on a complicated syntax, periodically save the current version under a different name.

To add, this way of versioning

  • PrepareData_v1.sps
  • PrepareData_v2.sps
  • PrepareData_v3.sps

looks better, clearly depicts work progress and is arranged alphabetically in the list of files. Compare with this one:

  • PrepareData 01.03.2013.sps
  • FINAL data preparation syntax.sps
  • !!!!VERY FINAL .sps