A lot of details around nobility change by the week or fortnight so maintaining a concise wiki detailing everything related would require immense manpower if not editing capability to every single noble house head. The cultures can be defined, but people already deviate from the cultures and play different ones that you better meet IC.

House Black presents a completely different New-Regalian culture compared to house Typhonus, and so does house d'Ortonnaise compared to house du Polignac (both Ithanian), or house Ravenstad compared to house Perigarten (both Leutz).