Data rules are useful when a form field does not contain free text, like comment or detailed description, but it must follow a pattern, for example a telephone number or the name of a city.

Data rules are checked during form processing after the text recognition. Each field where data rule is defined gets a flag showing whether the text matches the data rule or not.

Using data rules makes the form data extraction simpler, faster, and improves its accuracy.

Users can choose from the following types of data rule definition:

List of phrases

List of phrases is useful when the contents of the form is the part of a predefined list of words or phrases. The items of Wordlist can be single words or phrases containing multiple words.

Regular expression

CSDK supports Perl 4 style regular expressions. Almost all kind of syntaxes can be defined with regular expressions. Defining and evaluating these expressions can be difficult and time-consuming.

Easy mode: Logical expression for the containing characters

The supported logical expressions are more comfortable to use than regular expressions. The evaluation is very quick, and defining the rules is user friendly, but less type of syntaxes can be defined with logical expressions than with regular expressions. The following types of logical expressions are supported:

• The field can contain:

  • Lower case letters

  • Upper case letters

  • Digits

  • Spaces or tabs

  • +, -, and comma

  • Dots

  • Commas

  • Hyphens

  • Slashes (“/”)

  • List of specified characters

• The length of the field is between two specified numbers