Analysis codes allow you to 'tag' a field for a specific reason. An analysis code should be any very unique string. For example "First Wheat" would not be a good unique string, where as "Ftwhet" would be. Examples of analysis code use would be first, second crops. Different agronomists. Soil types. In fact anything you care to analyse.
Analysis codes are entered into the field's information:
You can then search for any combination of analysis code through the "Analysis Code" menu option:
The search type will search for either "AND", or "OR". "AND" will find any field with both codes, where "OR" will find fields with either code entered.