The Sagan Standard:

“Extraordinary claims require extraordinary evidence” (sometimes shortened to ECREE),[1] also known as the Sagan standard, is an aphorism popularized by science communicator Carl Sagan. He used the phrase in his 1979 book Broca’s Brain and the 1980 television program Cosmos. It has been described as fundamental to the scientific method and is regarded as encapsulating the basic principles of scientific skepticism.

The concept is similar to Occam’s razor in that both heuristics prefer simpler explanations of a phenomenon to more complicated ones. In application, there is some ambiguity regarding when evidence is deemed sufficiently “extraordinary”. It is often invoked to challenge data and scientific findings, or to criticize pseudoscientific claims. Some critics have argued that the standard can suppress innovation and affirm confirmation biases.

Hitchens’s razor:

Hitchens’s razor is an epistemological razor that serves as a general rule for rejecting certain knowledge claims. It states:

What can be asserted without evidence can also be dismissed without evidence.[1][2][3][a]

The razor is credited to author and journalist Christopher Hitchens, although its provenance can be traced to the Latin Quod gratis asseritur, gratis negatur (“What is asserted gratuitously is denied gratuitously”).[4] It implies that the burden of proof regarding the truthfulness of a claim lies with the one who makes the claim; if this burden is not met, then the claim is unfounded, and its opponents need not argue further in order to dismiss it. Hitchens used this phrase specifically in the context of refuting religious belief.[3]: 258 

Hat tip to Steve Stewart-Williams.