I am looking for a complete list of job categories and the relevant
job titles under each category (in txt format, or in any other format
would most likely be ok).  The categories and job titles should be
similar to those found here:

https://secure.salary.com/salaryreport/layoutscripts/srpl_overview_ext.asp
(First select Category, and then select Title)

These categories and titles will eventually be used as dropdown box selects (as
the example above), but I want to make sure that the list I am using
is not an infringement on anyone's intellectual property.

As a point of reference, a comprehensive list should have several
thousand job titles.  The example above has over 3000.