This question was closed as off topic, and there is a comment (though not by one of the close-voters) saying that it's off-topic but would be on topic at Unix.SE.
The question is undeniably about FreeBSD, in that it's asking how to remaster a FreeBSD ISO. But presumably, it's on topic for our site--after all, it's presumably about how to do it using Ubuntu. Furthermore, the specific information being requested doesn't seem to be particular to FreeBSD at all. This is asking how to remaster a bootable .iso
image.
Is the reason this was closed the assumption that the OP is not using Ubuntu? If so, why was this assumption made without asking in a comment? Or did the OP communicate with someone via other means (e.g., chat), indicating that he is not actually using Ubuntu?
If someone asks how to create a text document, or edit images, or access email, and they don't explicitly state they're using Ubuntu, we assume they are, or we ask if we're unsure. But for some other questions, involving another operating system, we seem to assume they are not running Ubuntu. (That is, if I'm recalling correctly, this doesn't seem like an isolated case.) Is there a good reason to assume that? Or is this just a mistake that's made frequently?