Is it okay to only list your 1st preference in the secondary school application form?

No - that advice is appalling. Shocking that a HT is saying that

You MUST put down all the schools you "wouldn't mind them going to" after you've listed the ones you want.
That MUST include one that you know you would get in to, otherwise, if you don't get your first choice, you will be allocated a school that no-one else wants to go to AND is miles and miles away from you.

That is a terrible idea. If you don't get a place at your preferred school and haven't identified second, third etc choices, your dc will be allocated any old place and it may well be in a school they'd hate in an area that's really tricky to get to and from. We've filled ds1's form up to avoid the chance of that happening.

No! And appalling that a HT is saying that to parents.

Read the old threads here.

In short you would be mad not to just list all your choices in genuine preference order and always have a banker - a school you are very likely to get into (usually the closest). Even if you don't like it, better to be at a bad school that's easy to get to than the bad one miles and miles from home that you may get if you fail to get any of your prefs.

Whether you list this secondary school, first or last it will not affect your position on it's list based on admission criteria. The only thing that would stop you getting it would be if you got a place at a school you listed as a higher pref.

If you only put one choice down and you don't get in then the LA will allocate you the nearest school that has places. This may be one that you would never have considered and is likely to some distance from where you live. This assumes that you live somewhere that still has schools with places when the allocations are made.

Use all your choices. Put your preferred school first and then rank the others into the next school you are happy to take and so on until you fill in the form.

If you meet the admissions criteria in more than one school you will be allocated a place at the one you placed highest on your form. This may be your first choice or it may be your sixth. The important thing is that it is a school you have chosen, rather than one that has been forced on you.

It's a bloody stupid idea and you've been very badly advised

Use all of your preferences

You have been badly advised.

I know someone who did this, she put an out of catchment school at number 1, and nothing at 2-5

No. She did not get the out of catchment school, and as she had not put the "good "catchment school on the list she didnot get that either. She ended up with a poor catchment school.

People treat this process like done psychological chess game, thinking: "if I only put 1 school down, they'll have to give me that one'". Well no.

You'll get given a school, but you'll most likely get the least popular one.

Noooo! That's not how it works!

There was a great thread on here recently about admissions myths and processes - mostly focused on primary schools, as that's usually the first time that parents have had to negotiate the system, but the principles still apply for secondary.

Basically, you don't have to be given any of your choices (they are preferences more than absolute choices); you will get the first school on the list where your child meets the admission criteria before the cohort for that year is full; and appeals are limited essentially to a mistake by the admission authority, not because you don't like the outcome.

Please ignore the head, and read the admissions information for your area very carefully indeed

No.

Use all your choices. The last one should be a school you're not necessarily keen on but is almost a dead cert catchment and better than a crap school 10 miles away.

If you fail your appeal you could be left with a terrible school miles away. I would not risk it.