Can multiple different HTML elements have the same ID if they're different elements?

Question

Can multiple HTML elements have the same ID if they\'re of different element types? Is a scenario like this valid? Eg:

div#foo
span#foo
a#foo

Answer 1

Nope, IDs have to be unique. You can use classes for that purpose

div.a {font: ...;}
/* or just: */
.a {prop: value;}