"death_flag" tag

from the death_flag wiki:

Pixiv Tag: 死亡フラグ (Shibou Furagu)

A sign to the audience that a character is about to die, and/or otherwise foreshadowing an imminent bad end.

A death flag is usually raised by a character saying or doing something that can be seen as tempting fate. Examples include: Doing something that he or she has been warned, sometimes repeatedly, could be fatal; an unrequited relationship suddenly and finally being requited, especially if it comes out of the blue; a promise to return just before leaving on a journey of uncertain length; and so on.

See also pool #1246.

Seems pretty subjective to me, and covered by pool #1246 already. Is this tag needed?

From where I sit, "Digging Your Own Grave" is more for overt actions and things that can be conveyed visually. The death_flag tag seems more fitting for saying something that could be seen as indirectly tempting fate, such as the examples listed in the description. It's a subtle, but distinct difference.