There is a well-known failure in technical writing where the person who knows a system best is the worst person to document it, because they have automated away every step that a newcomer trips on. Hosting has exactly this problem, and it produces guidebooks that explain the coffee machine in loving detail and say nothing about the front door needing a lift before the key turns.
The two categories
Everything in a property falls into one of two buckets.
Standard behaviour. A kettle. A fridge. A shower that turns on by turning the tap. Guests know these. Writing about them adds length and reduces the chance that anything is read.
Non-standard behaviour. Anything where the obvious action produces the wrong result. This is the entire useful content of an instructions section, and it is usually invisible to the person who lives with it.
The dividing line is sharp and easy to test: would a competent adult get this right on the first try without being told? If yes, delete it. If no, it goes in, with a photo.
How to find yours
You cannot introspect your way to this list. Three methods that work:
Read your own message history. Every explanation you have typed to a guest is a documented quirk. Search your threads for "you have to", "the trick is", "make sure you", and "it sometimes". Those four phrases will surface almost every one.
Ask the cleaner. Cleaners use the property harder than guests do and have no emotional investment in it being straightforward. Ask what they have to do differently here compared to their other properties. The answer is a list.
Watch one guest. If you ever do an in-person check-in, do not explain anything. Hand over the keys and watch for ninety seconds. Every hesitation is an entry.
A real list
This is the quirks section for one of my flats, in full. Fourteen items, and not one of them would occur to me unprompted.
- Front door: lift the handle up before turning the key, or the bolt won't clear.
- Hall light: on a timer, stays on about 90 seconds. The switch at the bottom of the stairs re-triggers it.
- Shower: push the dial in before turning it. It won't turn otherwise, and it does not feel like it should push.
- Hot water: takes about 40 seconds to arrive at the bathroom tap. It is not broken.
- Oven: Celsius, and it runs about 15 degrees hot. Recipes in Fahrenheit need converting; there's a chart inside the cupboard door.
- Hob: the front-left ring is the fast one. The back-right is very slow and everyone assumes it's broken.
- Dishwasher: tablets go in the small flap, not the open well. Programme 2 is the one to use — it's 90 minutes.
- Washing machine: the door stays locked for two minutes after the cycle ends.
- Thermostat: on a schedule. Hold the centre button for three seconds to override it until the morning.
- Radiator in the back bedroom: the valve sticks. Turn it hard, it won't break.
- TV: input 2 for the streaming stick, input 1 for aerial. The soundbar remote is the small black one in the drawer — the TV has no speakers of its own, so with the soundbar off there is no sound at all.
- Windows in the living room: the handle turns twice. First position is tilt, second is full open.
- Bathroom extractor: runs for fifteen minutes after the light goes off. It is loud. It is meant to.
- Bin cupboard in the hall: push the panel, there is no handle.
Fourteen items, about 260 words. That section prevented more messages than anything else I have ever written, including the WiFi.
Photograph the controls, not the appliances
A photo of your washing machine is useless. A photo of the dial with the correct programme circled is the instruction.
For anything with a panel, take one close photo with the relevant control marked and one sentence under it. Guests read the picture and skip the sentence, which is fine, because the picture already said it.
Say what is meant to happen
Half the "something is broken" messages are about correct behaviour that seems wrong. The extractor that runs on. The boiler that clicks. The fridge that hums for twenty minutes then stops. The underfloor heating that takes three hours to make a difference.
Each of those costs you a message unless you write one sentence saying it is normal. "The boiler clicks and whirs for a minute or two when hot water is drawn — that's it working, not failing" is a complete fix for a recurring complaint.
Keep it near the thing
The final move, and the one that determines whether any of this gets read: put the quirk where the guest will be when they hit it.
A single "house manual" page containing fourteen quirks in a list is a document nobody opens at the moment of confusion. The oven note belongs in the kitchen section. The shower note belongs in the bathroom section. The door note belongs in check-in, where a guest standing outside will already be looking.
The same fourteen facts, filed by room instead of by type, get found. That is the whole difference between a manual and a guidebook.