My two questions elaborated:
Charles V abdicated in ~1550. The titles of King of Hungary and Croatia,& Bohemia do not appear in his titles but appear in his brothers'. Why is it so?
Were Spain and Portugal ever officially declared as Empires? Charles V and his son Philip have only king of Spain and Portugal(only for the latter) in their titles whereas they are called empires in general. My understanding was that HRE and Russia were the only Empires in Christian Europe until Napoleon, and they claimed legitimacy from west and east Rome respectively.
The person in question's wiki page: Charles V
Regarding 1.
Kingdom of Hungary and Croatia were never parts of the HRE, and Charles V was never their king nor emperor.
After disastrous battle of Mohacs in 1526, where king of Hungary and Croatia died, their respective noblemen held congress to elect their kings. Without complicating the fact the nobility was divided between two candidates, the Croatian nobles Sabor (parliament) in Cetingrad in 1527 elected directly archduke Ferdinand as king of Croatia. So not Charles.
The same was pretty much in Hungary, in the rump diet of Bratislava where Ferdinand, not Charles, was elected king. But there the situation was even more divided, and outside my knowledge range.