How to scroll table's “tbody” independent of “thead”?

Question

As specified in the W3 specification for Tables:

Table rows may be grouped into a table head, table foot, and one or more table body sections, using

Answer 1

mandatory parts:

tbody {
    overflow-y: scroll;  (could be: 'overflow: scroll' for the two axes)
    display: block;
    with: xxx (a number or 100%)
}

thead {
    display: inline-block;
}