Debra Dalgliesh's Data Validation basics and how to set up dependent dropdowns

http://www.contextures.com/xlDataVal01.html


"I'm listening" wrote:

I want to create several drop down lists then make it conditional that users
select from these lists when entering data. For example, when the user
selects 'category A' (from a separate dropdown list), in the next column a
drop down list of items relative to category A would display, whereas, if the
user selectes category C, a different list relative to category C would and
display. I using Excel 2003.