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2/13/2003 version 0.1.0

o Initial release.

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2/26/2003 version 0.1.1

o Fixed validate method return value to reflect documented return value.
o Fixed a bug related to applying proc constraints.
o Fixed a bug in untainting of proc constraints.
o Wrote better unit tests.
o Code cleanup.

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4/8/2003 version 0.1.2

o Fixed constraint method to ignore empty fields.
o Fixed regexp_constraint method to ignore empty fields.
o Wrote additional unit test.

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8/14/2003 version 0.1.3

o Fixed credit card type detection bugs.
o Fixed a bug regarding invalid field accounting.

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10/26/2004 version 0.1.4

o Changed obsolete to_a() calls to use Array().
o Changed type() calls to use class().
o Fixed apply_string_constraint() to handle multiple elements.
o Fixed apply_regexp_constraint() to handle multiple elements.
o Remembered to increment version number.