Book that contains several Book 1's from different serieses

[Michele]

Several times I've run across a single publication that contains book 1's from several different serieses, for example:

Book: Rainy Day Romances
Get a taste of some great romance series! Contains:
-- Mary's Man (Second Chance Romance #1)
-- Tea and Sympathy (Coffee Shop Girls #1)
-- Walking the Dog (Pet Shop Cuties #1)


So, should the book "Rainy Day Romances" be added to each of those three serieses, as a non-primary work? Or should it not?

I'm thinking Not, because (a) Rainy Day Romances as a whole is not, in fact, part of any of these serieses, and besides (b) each individual book 1 is already part of its respective series, so adding Rainy Day Romances to all three serieses would be redundant.

Thanks!

[Renske]

They can be added in the way you describe. With short extra stories within a series it is done more often, as those are sometimes first or only published in an anthology.

[Michele]

So, "can be" but not "should be" ?