Screen Genius formats TV shows and their episodes like so:
Films: Italics
- Example: The Big Lebowski
Television Shows: Italics
- Example: Breaking Bad
Episodes of Television Shows: "Quotation marks"
- Example: "Hardhome"
tl;dr - these rules also apply to Doctor Who.
So why does this page exist then?
There's some grey area about what counts as an "episode".
From 1963-1989, most televised stories of Doctor Who were shown over 4-6 short episodes. The episodes often had titles of their own, but they are almost always referred to by the name of the serial.
Wikipedia classes the serials as longer works, and so formats 1963-89 serials in italics (The Caves Of Androzani). It then puts post-2005 episodes in quotation marks ("Rose"). To avoid confusion, Genius formats all stories as episodes - that is, in quotation marks.
There are a few exceptions, which will be detailed below.
1963-89 serial: "An Unearthly Child"
1996 movie: Doctor Who: The Movie
2005-present episode: "Blink"
Multi-part story: "The Pandorica Opens"/"The Big Bang"
A series-long story: The Trial Of A Time Lord
Episode is part of a multi-part story or series-long story: "Heaven Sent"
Episode also released as a film: "The Day of the Doctor"
Non-televised stories
Unfilmed scripts: "The Giants"
Minisode: "The Night Of The Doctor"
Minisode series: Pond Life
Big Finish audio plays: Jubilee
Novels: Shada
Short stories: "Nothing O'Clock"
Short story collections: Summer Falls
Comic strips and Graphic Novels: The Cruel Sea