Roman dial numbers ?????

[acadianl79]

Here's a quick question...

Most watches with a roman dial have the IIII symbol at the 4 o'clock position.

I always thought that the number 4 was represented by the roman symbol IV.

Then why the use the symbol IIII ?

A lot of Patek watches have the IIII symbol
some Patek have the IV symbol ????

Is there a standard for roman numbers ?