Not sure if this is a right place to ask this question, but I'll have a go.
What do you call the ends of an apple, as in, the branch side, and its opposite side where it's caved in?
Learn English – Name(s) for the top and bottom of an apple
vocabulary
Related Solutions
The actual residence of a person is referred to as their "home address". Since you refer to taxes, this is what the IRS Form 1040 (the personal income tax form in the United States) asks for. An address where they can be contacted is referred to as their "mailing address". This can be a Post Office Box (P.O. Box) where mail is held for them until they retrieve it.
However, there is no common term for what you are describing—at least in the United States, the government does not restrict where someone is entitled to live (except in the form of required property taxes and the like). For senior government officials, especially diplomats, however, there is the term "official residence", but this generally does not apply outside of government.
If you rent a flat from the government (does it happen in your country?) how do you call the right to use this flat?
At least in the United States, property is owned by legal persons, which can be an individual or a corporation; i.e. people own the houses, apartments (flats), office buildings, etc. themselves and they may rent them out to others. The term "tenant" or "lessee" describes someone having paid the rent; the noun "lease" describes the agreement between the two parties; the term "lessor" describes the person who owns the property and is renting it out.
Although the government does own some of the buildings it operates offices in, it also rents other offices—in this respect, the government is not supreme—it is not the supreme owner of all the land. (Although in a few unusual circumstances, it may rent out some living/building space, but this is by no means the norm, and it would be the same as renting from any other person, so there is no special term). Legally speaking, there is the power of eminent domain, enacted by the Fifth Amendment to the Constitution, but it requires that people be paid if the government seizes the land, which it only does so in exceptional circumstances (e.g. public safety).
N.B.: Note that while I generally use the verb "rent" in this answer so as not to confuse the verb "lease" and the noun "lease", the verb "lease" means the same thing as "rent".
The "spine" of both the leaf and each pinna of the leaf appears to be called the midrib.
[Adityamadhav83 via Wikimedia]
Cocos nucifera is a large palm, growing up to 30 m (98 ft) tall, with pinnate leaves 4–6 m (13–20 ft) long, and pinnae 60–90 cm long
Pinnately veined leaves have one large central vein, called the midrib, which extends from the base of the blade to its tip.
midrib
A large strengthened vein along the midline of a leaf.[ODO]
Best Answer
The ends don't appear to have technical names, but the parts at each end do.
The stem is also called the pedicel or stalk.
The opposite end is where the stamen is located. In the second picture below, this end is also referred to as the style.
None of these terms are common outside of technical usage when discussing plant, flower, and fruit morphology. More common descriptors are stem end and tip.
By the way, some pictures will show the "calyx" (derived from "cup" or "chalice"), often at the tip end. But I believe the calyx is a depression at either end. Referring to a particular calyx requires a modifier (e.g., pedicel calyx).