There are actually three different versions of the first Bat Family Crossover, all of which contradict one another and the series themselves. The short film, the movie and the DS game each have the teams meeting for the first time under different circumstances; only the movie and their sequels include Fresh and all the seasons after it; only the DS game takes place while the series are all running, while the others take place after they are over; and the short film just makes no sense whatsoever.
Name's the Same: Several seasons tend to repeat names from previous continuities. So far the repeated names were Nozomi (Max Heart and Yes!5), Kaoru (Splash Star, Fresh, and — if it counts — Kaoruko from Heartcatch), Rin (Yes! 5 and Happiness Charge), Hayato (Fresh and Heartcatch), Kurumi (Yes!5 [given name], Heartcatch [surname]), Miyuki (Fresh and Smile), Akane (the original/Max Heart and Smile), Nao (Max Heart, Heartcatch and Smile), Reika (Fresh and Smile), Ayumi (Fresh, Heartcatch, All Stars New Stage and Doki Doki), Madoka (Yes!5 [given name], Doki Doki [surname]), Megumi (Yes!5 and Happiness Charge) and Seiji (Doki Doki and Happiness Charge).
No Export for You: The English dub of Futari wa Pretty Cure only aired in Canada and the UK. None of the other seasons have been dubbed yet. There are reports that Saban Brands has the rights to air Precure internationally but despite rumors, no Precure dub has been forthcoming.