12 lb line on spinning rod

I am a trout angler and I usually post on flyfishing.co.uk but I thought I'd post this here as I cannot post it there.

I was wondering if I am able to put 12lb line on a rod which I usually have 6 lb line on it.I have got the rod ages ago and I was told it is ok with 6lb.I think it is 4-8lb but could I put 12lb on it without it breaking?

Is the line rating just marketing BS as I have heard elsewhere or is it important?

Thanks

There's nothing stopping you it's your rod but the rod as you say is rated 4-8lbs which is the manufactures guide for that rod, you do stand the risk of braking the rod
I have landed 10lbs fish on 6lbs braking strain of the line

Perhaps I got this all wrong, but as a fly fisherman I would think that you realise the importance of ''balanced'' tackle.

As Chrissh points out, there is a distinct possibility of breaking the rod.

Might I ask what species you are targeting to step up the line rating?

What's your target species and weight? 12lb is pretty heavy.

I do a fair amount of lure fishing and find that any numbers printed on light spinning/lure rods usually have a 'g' on the end (i.e. gram) displayed as 5-30g and would refer to the weight of lures used. These rods are very light but usually used with 10/12lb braid and if drop shotting a 6lb fluoro leader would be attached. There would be no problem with the rod landing a 10lb pike. The line may seem over gunned for perch, chub, jacks or zander but its to do with the amount of hook-ups on snags whilst jigging or drop shotting. If knowingly targeting bigger fish then the rod needs a bigger rating i.e. 10-40g.