Editing Philately (section)

==Diversification==
Expanding range of activity:<ref>{{Cite book|last=Brennan|first=Sheila|url=https://books.google.com/books?id=eeFdDwAAQBAJ&q=types+of+philately|title=Stamping American Memory: Collectors, Citizens, and the Post|date=2018-06-15|publisher=University of Michigan Press|isbn=978-0-472-13086-3|language=en}}</ref><!-- The reference was previously inside the subsection name. It is not clear what specifically it is related to. --> 
* [[Topical stamp collecting|Thematic philately]], also known as topical philately, is the study of what is depicted on individual stamps. There are hundreds of popular subjects, such as birds, and ships, poets, presidents, monarchs, maps, aircraft, spacecraft, sports, and insects on stamps. Stamps depicted on stamps also constitute a topical area of collecting. Interesting aspects of topical philately include design mistakes and alterations; for instance, the recent editing out of cigarettes from the pictures used for United States stamps, and the stories of how particular images came to be used.
* [[Postal history]] studies the postal systems and how they operate and, or, the study of postage stamps and covers and associated material illustrating historical episodes of postal systems both before and after the introduction of the adhesive stamps. It includes the study of [[postmark]]s, [[post office]]s, [[Postal Authorities|postal authorities]], postal rates and regulations and the process by which letters are moved from sender to recipient, including routes and choice of conveyance.  A classic example is the [[Pony Express]], which was the fastest way to send letters across the United States during the few months that it operated.  [[Cover (philately)|Covers]] that can be proven to have been sent by the Pony Express are highly prized by collectors.
* [[Aerophilately]] is the branch of postal history that specializes in the study of [[airmail]]. Philatelists have observed the development of mail transport by air from its beginning, and all aspects of airmail services have been extensively studied and documented by specialists.
*[[Astrophilately]] is the branch of postal history that specializes in the study of stamps and postmarked envelopes that are connected to outer space.
* [[Postal stationery]] includes [[stamped envelope]]s, [[postal card]]s, [[letter sheet]]s, [[Aerogram|aérogramme]]s (airletter sheets) and [[Wrapper (philately)|wrappers]], most of which have an [[Embossing (paper)|embossed]] or [[imprinted stamp]] or [[Indicia (philately)|indicia]] indicating the prepayment of postage.
* [[Cinderella stamp|Erinnophilia]] is the study of objects (cinderella stamps) that look like stamps, but are not postage stamps. Examples include [[Easter seals (philately)|Easter Seals]], [[Christmas Seal]]s, propaganda labels, and so forth.
* [[Philatelic literature]] documents the results of the philatelic study and includes thousands of books and periodicals.
* [[Revenue stamp|Revenue philately]] is the study of stamps used to collect taxes or fees on such things as legal documents, court fees, receipts, tobacco, alcoholic drinks, drugs and medicines, playing cards, hunting licenses and newspapers.
* [[Maximaphily]] is the study of Maximum Cards. Maximum Cards can be defined as a picture postcard with a postage stamp on the same theme and cancellation, with a maximum concordance between all three.
* [[Letterlocking]] includes "the process of folding and securing of letter substrates to become their own envelopes" or to create a form of "tamper-evident locking mechanism."<ref>{{cite journal |title=Unlocking history through automated virtual unfolding of sealed documents imaged by X-ray microtomography |last1=Dambrogio |first1=Jana |last2=Ghassaei |first2=Amanda |last3=Staraza Smith |first3=Daniel |last4=Jackson |first4=Holly |last5=Demaine |first5=Martin L.|date=2 March 2021 |journal=Nature Communications |volume=12 |issue=1 |page=1184 |doi=10.1038/s41467-021-21326-w |pmid=33654094 |pmc=7925573 |bibcode=2021NatCo..12.1184D }}</ref><ref>{{cite web |title=A Letter Sealed for Centuries Has Been Read—Without Even Opening It |url= https://www.wsj.com/articles/a-letter-sealed-for-centuries-has-been-readwithout-even-opening-it-11614679203 |last=Castellanos |first= Sara |date=2 March 2021 |access-date=2 March 2021 |work= The Wall Street Journal}}</ref>