How to create Sequel show relation or do we have alternative for it?

Franchise would be the best match, taken from the data policies:

Franchise

A show that's closely related to an existing show; because they share a similar name and premise, (main) crew or cast members portraying the same character, cinematic universe, and/or a continous storyline. This relation only applies when the similarites are present for the majority of the show's run; an occasional "crossover episode" between two shows that otherwise share no similarities does not warrant creating a show relation.

Only if it doesn't fall under this category, again taken from the data policies:

Continuations/reboots

A continuation/reboot is a show with the same name and theme as a previously ended show. Depending on the circumstances, a continuation should be added as a whole new show entry, or as a new season on the existing show entry.

Only if all of the following are true, the continuation should be part of the existing show entry:

The new network/web channel refers to the show as a continuation

The new network/web channel does not refer to the pilot as "season 1"

At least one of the previous show's creators or executive producers is involved with the continuation

At least one of the previous show's main cast members is starring in the continuation

In all other cases, a new show entry should be created.

https://www.tvmaze.com/faqs/9/data-policies
 

Thanks. Reboot and Continuation are two very different things.

I marked Mike Hammer show as a Reboot of Mickey Spillane's Mike Hammer show because it's the same "universe" just starting anew with new cast and everything.

But Mike Hammer, Private Eye is a reboot-continuation. Not so much of a reboot, but a continuation with obviously older Mike Hammer and same agency but new side characters (well his secretary was same and just as young, so it feels like a reboot, lol).

I noticed that sometimes we put new shows just as another season to existing ones, as it mentions in the policy about continuations, but the more I think about this, the more it feels like a Reboot... but also kind of a continuation since they weren't doing all the same cases.

I think here it would also make more sense to mark it as Reboot to keep "Parent Show" connection.

So basically all three here would be (show 1) Parent - (show 2) Reboot / Parent -  (show 3) Reboot connected.
But does such connection indirectly mean that show 1 and show 3 should also have "Franchise" connection or does that disqualify reboots/remakes?

For example original Star Trek, and Star Trek TNG, and Star Trek Voyager are all part of the same universe and their story and setting fits and they are aware of each other (looking backward in time, that is) in its universe and may sometimes intertwine some episodes as such. That makes them all part of the same Franchise, right?

But if Star Trek (2009) theatrical movie was made as TV series, that would become Reboot of original Star Trek show and wouldn't be connected as "Franchise" any more, or would it have both connections, Franchise and Reboot?

@MAT13 wrote:
Thanks. Reboot and Continuation are two very different things.

I marked Mike Hammer show as a Reboot of Mickey Spillane's Mike Hammer show because it's the same "universe" just starting anew with new cast and everything.

But Mike Hammer, Private Eye is a reboot-continuation. Not so much of a reboot, but a continuation with obviously older Mike Hammer and same agency but new side characters (well his secretary was same and just as young, so it feels like a reboot, lol).

I noticed that sometimes we put new shows just as another season to existing ones, as it mentions in the policy about continuations, but the more I think about this, the more it feels like a Reboot... but also kind of a continuation since they weren't doing all the same cases.

I think here it would also make more sense to mark it as Reboot to keep "Parent Show" connection.

So basically all three here would be (show 1) Parent - (show 2) Reboot / Parent -  (show 3) Reboot connected.
But does such connection indirectly mean that show 1 and show 3 should also have "Franchise" connection or does that disqualify reboots/remakes?

For example original Star Trek, and Star Trek TNG, and Star Trek Voyager are all part of the same universe and their story and setting fits and they are aware of each other (looking backward in time, that is) in its universe and may sometimes intertwine some episodes as such. That makes them all part of the same Franchise, right?

But if Star Trek (2009) theatrical movie was made as TV series, that would become Reboot of original Star Trek show and wouldn't be connected as "Franchise" any more, or would it have both connections, Franchise and Reboot?

Rather then go on feelings have you researched to see if any press releases are available from the time to see what the network referred to it as? 

You can only link the show with one type of relationship. If a Star Trek series is made now with the same characters from the original series, for example Picard then it would be listed as a franchise of the original show because it meets the criteria listed in the data policies. 

https://www.tvmaze.com/shows/42193/star-trek-picard

I don't believe (I'm not a huge fan) the movies would meet franchise criteria so it would be listed as a reboot. 

@MAT13 wrote:
This Mike Hammer...

https://www.tvmaze.com/shows/2047/mike-hammer

...got a continuation... well, a new TV show which was sequel to this one.

And that is this show: https://www.tvmaze.com/shows/15091/mike-hammer-private-eye

However, I don't see any options that would indicate a direct sequel. Does "After Show" signify that?
Or should "Franchise" be selected there?
But "Franchise" is more for parallel shows that intertwine (i.e. Xena and Hercules, or Luke Cage and Jessica Jones), but here it's the same main cast actor playing same character it is just a continuation to the older show. If these were made as movies (like in Perry Mason, they'd just be added as specials to the old show, but because this is made as new TV series, it's a new show, so not sure how to connect them, the one is Parent Show, but the other isn't Reboot/Remake, but a continuation).

Sequels and spin-offs are both fits for the 'Franchise' relationship because they usually share some cast and crew, and their storyline is either continuous (sequel) or parallel (spin-off). This is the main difference between sequel and reboot.

So basically all three here would be (show 1) Parent - (show 2) Reboot / Parent -  (show 3) Reboot connected.
But does such connection indirectly mean that show 1 and show 3 should also have "Franchise" connection or does that disqualify reboots/remakes?

Indirect connections are added automatically, and they do not have a particular type. They are just 'indirect'. Two shows cannot have more than one relationship between them.

For example original Star Trek, and Star Trek TNG, and Star Trek Voyager are all part of the same universe and their story and setting fits and they are aware of each other (looking backward in time, that is) in its universe and may sometimes intertwine some episodes as such. That makes them all part of the same Franchise, right?

They also share some characters, which appeared in several shown. We're discussing now the possibility to add a 'Shared universe' type of relationship which will be suitable for shows only sharing a universe (MCU, Star Wars).