User Defined Fields (UDF's) are database fields that are set by the systems administrator when ProQuote is first configured. You can define as many UDF's as you require at the quote header level, the quote item level and price book item level. For each UDF you define the data format (numeric, text or memo) and assign a default value. A UDF can also be defined as a RULE. This type of UDF is able to store a formula that is used to calculate a value. See Business Rules for more information on rule based UDF's.