Because if you're in the sections where it refers to Subchapter N, Section 861, the presumption is that you are a nonresident alien. The only documents and regulations that refer to Subchapter N, Section 861 are those documents and regulations that a nonresident alien must use in order to determine and report his tax liability.
Why does Section 61 of the code have this cross reference?
Income from sources - Within the United States, see section 861 of this title Without the United States, see section 862 of this title Again, no mention of "ignore this if you are a US citizen working in the US."
The text you cited does not appear in Title26, Subtitle A, Chapter 1, Subchapter B, Part I, Section 61.
The totality of Section 61 is reprinted below:
Sec. 61. - Gross income defined
(a) General definition
Except as otherwise provided in this subtitle, gross income means all income from whatever source derived, including (but not limited to) the following items:
(1) Compensation for services, including fees, commissions, fringe benefits, and similar items;
(2) Gross income derived from business;
(3) Gains derived from dealings in property;
(4) Interest;
(5) Rents;
(6) Royalties;
(7) Dividends;
(8) Alimony and separate maintenance payments;
(9) Annuities;
(10) Income from life insurance and endowment contracts;
(11) Pensions;
(12) Income from discharge of indebtedness;
(13) Distributive share of partnership gross income;
(14) Income in respect of a decedent; and
(15) Income from an interest in an estate or trust.
(b) Cross references For items specifically included in gross income, see part II (sec. 71 and following). For items specifically excluded from gross income, see part III (sec. 101 and following)
As you can see, Section 61 makes NO MENTION of Section 861 whatsoever. Either you are misinformed--and quite badly misinformed, at that--or you are LYING.
Pray tell which one it is.
The book "United States Code" is not the law, it is a compilation of the law. The actual law is that which resides in U.S. Statutes, the published acts of Congress by date of enactment. Notes, Titles, labels etc added by West publishing for purposes of indexing and reference are not law.
Tell me where I can find that presumption in the statutes or regulations? Where does it say "ignore section 861 if you are not a nonresident alien?" What is your basis for that presumption?
Why does Section 61 of the code have this cross reference?
Income from sources -
Within the United States, see section 861 of this title
Without the United States, see section 862 of this title
Again, no mention of "ignore this if you are a US citizen working in the US."
The text you cited does not appear in Title26, Subtitle A, Chapter 1, Subchapter B, Part I, Section 61.
That is becuase it is a cross-reference, as I stated, from the annotated United States Code, not part of the statute itself.
While a cross-reference annotation or the index of the US Code does not carry legal weight, it serves as an aid for understanding the relationships between code sections. The cross reference here shows that Section 61 is related to Section 861 when it comes to determining income from sources within the United States.
Try to understand - a source of income is distinct from an item of income. Section 61 lists items of income, not sources.