Syncro without deleting nor adding file

[fujimoto2005]

I want to know how to get the settings of the following situation.
There are folders A and B. A part of the files in A exist in B.
For example, there are X, Y, Z, W files in A and X, Y in B.
When files in B are modified, I want to update the file in A.
Under the standard settings, Z and W in A are deleted since there are no Z and W in B,
But I want to prevent them from being deleted.
Also, I want to prevent X in A to be deleted even if file X in B is deleted.
In other words, I want to update only the existing files in B to A and not to reflect the information of deleting or adding the files in B.
Is there any way to set this situation?

Best regards.

[Plerry]

It seems you have to look into defining a Custom sync variant,
and define your preferred Action per Compare Category.