Why would Ilia put her oath of celibacy on record?

Question

One of the strangest moments in Star Trek: The Motion Picture is during Ilia and Kirk's first meeting where she bluntly tells him that his womanizing ways won't work on her:

My oath of celibacy is on record, Captain.

In all seriousness though, why did she put it on (presumably Starfleet's) official record? She certainly has the right to remain celibate for any reason she chooses to, but why get a higher authority involved?

The only reason I could think of is that if she had sex against her will, then it becomes supporting evidence to her legal argument that it was non-consensual because she officially declared that she was being celibate. However, that doesn't seem to match up with Gene Roddenberry's view of a utopic future, so I can't imagine that it was the intention.

So why would Ilia put her oath of celibacy on record, rather than just keeping it to herself?

Answer 1

Because she is a Deltan

From an early version of the script:

ILIA: I'm sworn to celibacy, Mister Sulu. That makes me as safe as any human female.

Sulu catches her eye but before he can reply, Decker has moved in beside Ilia.

DECKER: I know the Captain meant no personal insult.

ILIA: (eyes on console) I would never take advantage of a sexually immature species. (looks at him) You can assure him that's true, can't you?

Intercourse with a Deltan poses serious risks for non-Deltans. As such, Deltans entering Starfleet were required to take an oath of celibacy to avoid any fellow crew members being driven insane, etc.

“My oath of celibacy is on record, Captain.” Ilia kept her tone respectful. “May I assume my duties now?”

“By all means.” Kirk nodded. He was sorry her oath of celibacy had come up this way, but it was a Starfleet requirement wherever Deltans served with human crews.

—Star Trek:The Motion Picture (Novelization)

Sex is a particular risk:

Deltans tended to work and travel in groups, or at the very least in pairs, for a Deltan alone was terribly isolated. They required emotional and physical closeness of such intensity that no other sentient being could long survive intimacy with one of them.

—Star Trek: The Wrath of Khan (Novelization)

Indeed, even proximity to a Deltan could be risky, since they emit pheromones that can cause attraction in others. As such, the Deltan had better be dedicated to abstinence:

Kirk knew that the compelling attraction which Deltans exercised on anyone of the opposite sex went further than mere physical appearance; it was, literally, chemistry. Subliminal scents called pheromones were released by both Deltan males and females, triggering hormonal responses in most humanoid life forms of the opposite sex. It was especially troubling to humans since the scents were outside their normal olfactory range—just as a dog whistle is outside human hearing range. But the effects of these Deltan pheromones were still felt by them, and an unsuspecting human was likely to find himself in considerable sexual excitement without understanding why.

—Star Trek:The Motion Picture (Novelization)