In CircleCI, writing [ci skip] in the commit message allows you to skip CI execution.

• Skip a build - CircleCI
• Expand [ci skip] - Feature Request - CircleCI Community Discussion

(Example) Case where [ci skip] is included in commit message

$ git log origin/master..HEAD

commit 63ce74221ff899955dd6258020d6cb9accede893
Author: Daniel Woelfel 
Date:   Wed Jan 23 16:48:25 2013 -0800

    fix misspelling [ci skip]

commit 463147193b2fe561cfb12a9787434dd726390fcd
Author: Daniel Woelfel 
Date:   Wed Jan 23 16:30:24 2013 -0800

    add "Skip a build" doc

What is this magic comment…

That’s all from the Gemba - this is subtly convenient but commit messages might end up full of [ci skip].