Wiktionary
trigger warning
n. A notice placed before the beginning of media content (usually an online article, e-mail, or post) to warn of potential traumatic triggers it contains.
Wikipedia
Trigger Warning (album)
Trigger Warning is the fourth EP by the Australian electronic music duo Knife Party, released on 20 November 2015 by Earstorm Records and Big Beat. It is Knife Party's first EP since the release of their Haunted House EP in 2013. The EP's title is a reference to the colloquial term used to alert people to a potential trauma trigger of ensuing possible offensive content.
Usage examples of "trigger warning".
Of course, the failure of any one of them would trigger warning alarms, but even so she’.