Clearly cow identification?

Can “strangers” recognize your cows?

You probably know all your cows and don’t need the collar numbers or ear tags to know which cow it is.
But what if you go on holiday or for some other reason, perhaps suddenly, you need someone to take over your work. Can this person find the cows?

In other words: Is your cow identification in order? Are the numbers on the collars complete and legible to a stranger? Aren’t collars twisted, etc.?
When using ear tags as cow identification: are they complete and legible?