Re:
Under most rules you could do an XC race on an enduro bike - but not vice-versa.
Don't believe though that this is in any way retro v modern in terms of 'standards'.
There been many frustrated would-be entrants turned away from an enduro race for not having a full-face helmet, or kneepads (where often the pads are still optional in DH!). 'What is Enduro' and the associated 'WTF can I ride on/in' has been quite a bone of contention in the past few years. And with everyone and their dog being instructed they need a trail/traow boike; they just aren't going to suit all courses.
The last 2 races near to me were organised by different clubs (one a self-styled serious club/authority; the other an anti-car environmentalist group posing as a Bike Group; yet they had the better attitudes..).
The Authority stated your bike MUST be scrutineered, between sign-in and racing; you also had to pay your £10 fee a month in advance, for 2x DH runs with one walk of the track allowed beforehand - but set no regulations. IF your bike did not pass scrutineering, you shall not race; yet no regs were set out! :facepalm:
(This same club also organises road race/sportives, again £10 entry and gives you the route, but does not marshal or signpost the routes, so if you don't know where 'Stinkman's Lane' is, or which direction is 'proceeding southeast' you're out of luck.)
The 'fun' club organises XCCX races (Xc bikes, rigid 29ers, XC machinery all welcome), including some with a beer/cider pits each lap. Great!
Except they won't tell you where to go or where places are; so if you don't know where the entrance to the west gate of the cider orchard is, by 8am...
How hard is it for people to draw a clear map these days, and to be organised? In the old days of the Grundig at Plymouth, everything was well set out & maps (albeit hand-drawn) were photocopied or scanned & passed around. Same at Woodbury XC races (and that's not a small place)
Google Maps is no help, as for things local out in't sticks; it's only accurate to about 1/2 a mile, that's a long way in country lanes at 7:30 am trying to find somewhere that isn't signposted.. I've not encountered such issues trying to find Karting tracks; they know how to plot maps.
When I compare school jumble sales, Church fetes, kids birthday parties and the efforts people go to to organise, map, sign or direct... My take on it is that if a cycle/bike club can't be arsed to make at least that much effort for something they are demanding £10 for-with no promise that you will actually be allowed to participate- then my £10 will stay in my pocket as my emergency money for my own 'freeride', on my own time, where I choose.
Perhaps I'm just a miserable git, but perhaps some of these races don't deserve entrants if they can't make the effort they expect of you.