What are philatelists?

Some articles on philatelists:

Postage Stamps And Postal History Of Turkey
... stamp issues between 1863 and 1888 are popular among philatelists, and its postal cancellations have received extensive study ... Philatelists collect Turkish stamps used in various parts of the Ottoman Empire, such as Palestine, Jordan, Lebanon, and Greece ... also have a complex history of overprints of interest to philatelists ...
Plating (philately) - Classic Issues
... Philatelists have made extensive efforts in plating many of the Nineteenth Century Classic postage stamp issues and have written a number of books on plating different stamp issues ... Through painstaking study of the stamps, philatelists were able to reconstruct most or all of the first Die II's 70 plates ... Later philatelists were assisted when reference copies and high quality photographs of the original panes kept by the British Government were made available for inspection ...