verify element content model (element-permitted-occurrences)

Some elements may only be used a fixed amount of times in given context.

Rule details

Examples of incorrect code for this rule:

<!-- table footer can only be used once -->
<table>
    <tfoot></tfoot>
    <tfoot></tfoot>
</div>
4:6 - Element <tfoot> can only appear once under <table>

Examples of correct code for this rule:

<table>
    <tfoot></tfoot>
</table>