How do section titles impact the interpretation of body text in a contract?

Question

There is a contract between Party A and Party S. Party A is the author of the contract. And Party S signed it.

In the contract, there are two sections, titled "Responsibilities of Party A" and "Responsibilities of Party S". Each section lists several bulleted responsibilities. However, one of the bullet points in "Responsibilities of Party A" includes "Party S will not do X". For example:

Responsibilities of Party A

• Party A will do V.
• Party A won't do W.
• Party S will not publicly disclose information received uniquely from Party A.
• Party A will do Y.
• Party A won't do Z.

Is Party S contractually responsible for the stated responsibility/prohibition? Does the section header matter?

Answer 1

Headings can be used to inform the interpretation of the operative clauses. See Neely v. MacDonald, 2014 ONCA 874, at para 11, citations removed:

The headings contained in a contract are part of the language chosen by the parties and can properly be considered in interpreting the provisions that follow, provided the wording of the contract is not inconsistent with such an interpretation. Failure to read an agreement in accordance with its headings may lead a court to misconstrue the contractual provisions.

See also at Toronto (City) v. Toronto Railway Co., [1907] A.C. 315 (P.C.), p. 324:

as was held in Hammersmith Ry. Co. v. Brand, such a heading is to be regarded as giving the key to the interpretation of the clauses ranged under it, unless the wording is inconsistent with such interpretation.

However, the contract itself can contain a clause precluding any reliance on the headings for interpretive purposes.