The first number behind to [ will to combine with the number range into the [], the | divides the elements, and the [/ . -] are the delimiters
//Maximo 10 caracteres, mayusculas, minusculas y numero
^[a-zA-Z0-9]{0,10}$
//Máximo 10 dígitos
^[0-9]{0,10}$
//MM/DD/YYYY
^(0[1-9]|[12][0-9]|3[01])[- /.](0[1-9]|1[012])[- /.](19|20)\d\d$
//MM/DD/YY
^(0[1-9]|[12][0-9]|3[01])[/](0[1-9]|1[012])[/](0[1-9]|[1][7-9]|[2-5][0-9])$
//MMDDYY
^(0[1-9]|[12][0-9]|3[01])(0[1-9]|1[012])(0[1-9]|[1][7-9]|[2-5][0-9])$