I wanted to know if there was any regulations for boots (The size of the upper part and collar of the boots), if so what are they?
The bit you can’t see?
In all seriousness, there must be a reason for your query? If you are specific it may help get the correct answer.
Easier to link to an example of something you’re looking at and ask if it’s suitable - there’s so many ways to describe and interpretations thereof (and products purporting to be something they aren’t).
Generally, my description would be something “high-leg/above the ankle, described as combat/assault/patrol boot, black or brown”.
But not everything matching that description will necessarily be suitable for use and there’s a range of budgets.
Doing lots of FT - slightly better quality and full leather or Gore-tex.
Mooching about the unit and maybe a bit of shooting - nothing special, fabric without Gore-tex probably not an issue.
I would say the lowest boot you want to go for is one like the AKU Pilgrim which is on issue. Any shorter and it won’t give appropriate support and won’t look right in uniform.
The issue ones have a bit of a reputation as ankle breakers, they have the cheaper sole and are lower cut than the civvie version so although they are light they’re not great.
The cut is exactly the same - they are not lower. They are a bit cheaper made but work fine. The only major issue is quality control on the goretex lining. This is solved by buying the non-issue version.
There is actually now a high leg version which I believe it actually made by Aku.
The elephant in this room is that now we’ve gone over to brown boots there’s a huge overlap between the boots you’d use with MTP to shoot on a range, and the boots you’d wear on a DofE expedition.
In answer to the OP’s specific question, I’ve seen no evidence that there is any ACO ruling/diktat regarding the specific boots to be worn with MTP/DPM: as long as they are brown and meet your trousers it would appear than no one cares. What then matters is what fits, what you want them for, and what you can afford.
Tell us what what you want them for - L85 shooting on a station range? Sitting in the office looking ally? 5 days of wading through streams, mud, and walking 50 miles carrying a 25kg rucksack through Snowdonia in April? - then tell us what you can afford, and we’ll try and sort you out…
There are two cuts of boot from AKU, always has been in the civvie variant, the MOD have just had the HL version in response to the ankle issues, below are the two different variants.
I know, I’ve been buying them for years.
The HL FG boot is new, previously you had to be the version with suede leather (not that it really mattered) to get HL. I haven’t tried them, but these ones are actually made by Aku, as opposed to the MOD contract boots which were not.