Field markings

[SamG]

I don't want to assume...

While watching the recent bowl games (I think they were all at NFL stadium), I noticed additional "hash marks" (for lack of a better term) outside the numbers painted on the field. It looked like a pair on either side of the field.

Now the assumption... do those marks indicate where the 'numbers' would be for a college field?

And just for clarification, when do players need to be "between the numbers"?

Thanks

[HLin NC]

NFL- bottom of the number is 12 yards off the sideline

NCAA- top of the number is 9 yards off the sideline

b. Nine-Yard Marks.
1. Each Team A substitute must have been between the nine-yard marks.
Team A players who participated in the previous down must have been
between the nine-yard marks after the previous down and before the next
snap (A.R. 3-3-4-I).
2. All Team A players must have been between the nine-yard marks after a
charged team timeout, an injury timeout, a media timeout or the end of
a period.

[SamG]

Thank you!