kanji - Use of 旧字体 in Japanese names

Currently, the kanji used in registering names in Japan are restricted to those from the 常用漢字 and the 人名用漢字 lists. Since this is the case, why do some names include kanji not on the list like 澤 (for example 花澤香菜)? It's true that 澤 is the 旧字体 form of 沢, which has been on the 常用 list since its inception in 1981, but 澤 is not and does not seem to ever have been a valid name kanji. (Of course, 旧字体 on the 人名用 list like 彌 are allowed to be used in names, but 澤 is not one of those.)

This answer provides some clues, stating that all 旧字体 forms of official characters are permitted in names, so 澤 would be allowed. However, the responses to this question seem to imply that only 旧字体 that are included in the 常用 or 人名用 lists are permitted, so 澤 would not be allowed.

Therefore, why does 花澤香菜 have 澤 in her name? Is there a surname exception that allows 旧字体 to be used? Was there a law change between 1989 (her birth year) and the present that prevented the use of 旧字体? Was 澤 actually once included in the 人名用 list? Or is it something else entirely?

Answer

Perhaps it's simply because her family name, 花澤, had been used before the use of 澤 was prohibited in 1948. (BTW, 花澤香菜 is a 芸能人 but this seems to be her real name.)

You cannot use 澤 for given names of newly-born babies today. (i.e., 沢子 will be accepted by the government, but 澤子 is not).

However, kanji of existing names (including both family names and given names) were not changed in the government registry after the law took effect. As a natural consequence, there are many people who have kanji not listed on today's 常用/人名 kanji lists, especially in their family names.

Some people take pride in having 旧字体/異体字 family names and keep on using them whenever possible (which can be troublesome because some of them even don't have character codes). But some people choose to use 常用漢字 versions in their everyday life while still having 旧字体 names registered in the government (which can be troublesome, too). Fortunately, it's possible to change kanji registered in the family registry from 旧字体 to 新字体 (with a rather simple procedure), but unless one does that, they will inherit the family name from their parents which may contain 旧字体 kanji.

As for 澤, it's a very common kanji found in family names, and I think most people are even unaware that it's not 人名漢字.