Learn English – Capitalisation of “Many thanks” as a stand-alone term

When you speak of capitalizing a word, that normally means to capitalize only the first letter. If you were to say "capitalize all the words that appear in the table headers", I believe this would get your meaning across fine (and as always in specifications, a little example goes a very long way).

The only other likely interpretation, putting it in all caps, is not normally expressed that way; usually one would have to say "put the words that appear in the table headers in all caps" to communicate that.

Sometimes it is a matter distinguishing between two uses of the same word. For example:

catholic - all-embracing

Catholic - of the Roman Catholic church

chair - a seat with a backrest

Chair - person who runs the meeting (also chairperson, formerly chairman)

conservative - averse to change, very traditional

Conservative - right-wing political party

deaf - inability to hear

Deaf - a cultural adjective, meaning active within the Deaf community

Further, CamelCase (as it is known) can be useful for separating words when spaces cannot be used, such as in web/email addresses.