Having spoken with the organiser today, I actually now get the impression that its not quite a big a deal of an event as I had originally thought, despite the fancy location. Its actually being organised for charity by one of the individual stores, rather than say the brand's head office launching the collection, which I'm sure they would have no doubt had a paid photographer for.
There also won't be any kind of raised catwalk and there won't be any stage lighting, so it was suggested that I obviously use flash.... which given if it had been a pro catwalk, is apparently not allowed. In terms of myself, that means a bit more time experimenting to get the lighting right and consistent.
To also demonstrate how its a bit less professional than anticipated, the organiser apparently had me and a videographer penciled in as midway down the catwalk, side-on. I pointed out that this was not the best angle to be taking photos from, and you typically need to be shooting from the end of the catwalk where they stop to pose. So now they are rearranging some seats to do so!
Well whatever you do, I would suggest drawing a up a little contract to say what you'll be delivering and where they can use them.
Yeah I already have a proper photography licensing contract that I've used before when I've made sales. So I will tailor it to exactly what the shoot brief was, which was to provide them with images of the event for the website and social media. So the licence will demonstrate that, along with explaining something along the lines of it being ok to submit to press, however there is no free usage and as such any publications will have to contact/pay me at standard NUJ rates for the type of page/size its used on.
What I think I might also make sense, is before I even send them the finished images, just submit some to Picture Editors at the fashion magazines. If that is what they are going to end up doing anyway, I've got the jump on them in ensuring that I get paid when its used.