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So the issue regarding the Bourbon-Parma is that their official titles are not "Prince(ss) of the Netherlands" or "Prince(ss) of Orange-Nassau". Their titles as listed here https://www.hogeraadvanadel.nl/adel/nederlandse-adellijke-families/noord-nederlandse-adellijke-families are in the Dutch nobility, which is different from the listed royal titles mentioned and are more similar to titles such as Prince de Chimay and Prince of Waterloo. While they are undoubtedly part of the extended Dutch Royal family, so are people like Countess Eloise of Orange-Nassau and Bernardo Guillermo, who are not listed in these templates as they don't hold the titles "Prince(ss) of the Netherlands" or "Prince(ss) of Orange-Nassau". The situation with the children of Princess Irene is similar. It's worth noting that them being added here is a recent addition. 2601:249:9301:D570:E8D7:AA7:C58A:3A0C (talk) 06:56, 20 December 2022 (UTC)[reply]__DTELLIPSISBUTTON__{"threadItem":{"timestamp":"20221220065600","author":"2601:249:9301:D570:E8D7:AA7:C58A:3A0C","type":"comment","level":1,"id":"c-2601:249:9301:D570:E8D7:AA7:C58A:3A0C-20221220065600-Bourbon-Parma","replies":["c-Thinker78-20221224011000-2601:249:9301:D570:E8D7:AA7:C58A:3A0C-20221220065600"]}}-->
As I see, the purpose of this template may not be just to list the royal family but rather all the Dutch princes who descend from William I. In the nobility website you shared, there is only one contemporary prince (Bourbon de Parme), so I don't see an issue with him being included. Thinker78(talk)01:10, 24 December 2022 (UTC)[reply]__DTELLIPSISBUTTON__{"threadItem":{"timestamp":"20221224011000","author":"Thinker78","type":"comment","level":2,"id":"c-Thinker78-20221224011000-2601:249:9301:D570:E8D7:AA7:C58A:3A0C-20221220065600","replies":[]}}-->