And it can disguise from the outsider another crucial feature.

This makes quantum field theories especially useful for describing systems where the particle count/number may change over time, a crucial feature of relativistic dynamics.

Two crucial features - social mobility and the stretching of able pupils - were sacrificed in favour of prizes for all in a mediocre system aimed at middle-ability students.

Studies of their forgeries revealed that they were continually trying to improve their product, but crucial features of the genuine note remained elusive.

Coding and designing for uncertain future requirements implies the risk of spending resources on something that might not be needed, while perhaps delaying crucial features.