Reasons why a person cannot inherit a title

I am compiling a list of the reasons why a person would not be allowed to
inherit a royal or noble title. So far, I have the following :

1. Barred by the rules of succession or the remainder
2. Not born within lawful wedlock
3. The product of a morganatic marriage

Stan Brown...

I think (2) and (3) are special cases of (1).

pierre_aronax...

But (1) is not homogenous: the rules of succession and the remainder
are not one and the same thing. In the case of a British peerage for
example, a daughter born in lawful wedlock is barred by the wording of
the remainder, when a son born before marriage is barred by the
(general) rules of succession.

sionevar...

That leads me to ask, how and where are the rules for morganatic marriage
enshrined? Is there a legal process to be followed, or is it simply a
decision taken by the head of the family?

pierre_aronax...

Morganatic marriages are a specific kind of marriage contracts which
existed only in the German nobility (and not only in reigning houses).
They must not be confused with unauthorized marriages or unequal
marriages which were introduced relatively recently in reigning houses
or assimilates, often by constitutional devices, to prevent any kind of
unwanted alliances.

I would be particularly interested to know if there are titles which require
a person to use a certain family name, or to not already be in possession of
a hereditary dignity.

I would appreciate any help you have to offer.