Paragraph after invalid sole OPTION

Paragraph before invalid sole OPTGROUP

Invalid span inside OPTGROUP Invalid text inside

Paragraph after invalid OPTGROUP and valid mixed SELECT with and without OPTGROUP

Paragraph after valid mixed SELECT with and without OPTGROUP and before invalid mixed unclosed OPTION/OPTGROUP

Paragraph after invalid mixed unclosed OPTION/OPTGROUP. In web-browsers (Firefox and Chrome) this P and all consecutive content is invisibleMDN