Актуализация...персональных данных

05:32 Aug 3, 2019 

The Misha: good point.

22:54 Aug 2, 2019 

If you start with an -ing form in the string, you want to continue with it rather than mix and match it with regular nouns. It's not a question of strict grammar rules per se, but mostly of style. Besides, when you put an -ing form next to a noun like this, that -ing form becomes a verbal noun itself rather than the gerund, which is still a verbal form, which means that, technically, instead of using the gerund, as in "updating personal data," you have to use the verbal noun, which would make it "updating OF personal data," and it then becomes one unholy mess.

22:54 Aug 2, 2019 

If you start with an -ing form in the string, you want to continue with it rather than mix and match it with regular nouns. It's not a question of strict grammar rules per se, but mostly of style. Besides, when you put an -ing form next to a noun like this, that -ing form becomes a verbal noun itself rather than the gerund, which is still a verbal form, which means that, technically, instead of using the gerund, as in "updating personal data," you have to use the verbal noun, which would make it "updating OF personal data," and it then becomes one unholy mess.

20:12 Aug 2, 2019 

.

20:05 Aug 2, 2019 

IMHO. Допускается всё, что Вам нравится (в том числе сочетания герундия и любых иных словоформ). Никаких строгих правил на этот счет нет. Главное, чтобы читателю было понятно, о чем идёт речь.