Here are the possible solutions for it's needed for self checkout clue
Answer
Clue
Relevancy
barcode
Clue
It's needed for self-checkout
Definition
an arrangement, readable by computer, of thick and thin parallel lines, e.g. printed on, and giving coded details of, goods at a point of sale, library books, etc.
scan
Clue
Do some self-checkout work
upc
Clue
Lines at a self-checkout
amiok
Clue
Self-evaluating question for the self-help crowd
dignity
Clue
Self of self-respect
Definition
the state of being dignified
humblebrag
Clue
Self-praise couched in self-deprecation, in modern lingo
Definition
to make a statement that purports to be self-effacing but in fact reveals a person's wealth or importance
mac
Clue
Self-described self-defense expert on "It's Always Sunny in Philadelphia"