raft

Raft = a floatation device, rare on deserted islands.

Raft, to mean a large amount of, dates from the 1800s and still manages to upset a lot of people. Some argue that it is overused, but it is just as good as the alternatives: host, range, number etc.

raise children or bring up children?

bring up children: It is an American practice to speak of "raising your kids" but the British prefer to say "bring up children".

rancour or rancor?

rancour: .

rateable or ratable?

rateable:

ravelled or raveled?

In British English it is ravelled (unravelled) and in US English it is raveled (unraveled).

ravelling or raveling?

In British English it is ravelling (unravelling) and in US English it is raveling (unraveling).

rearwards or rearward?

rearwards: The only time that British English uses rearward is before a noun, such as a rearward glance. What this entry is referring to is where these types of words appear after a verb. British practice uses to look rearwards while only the Americans use to look rearward.

reconcilable or reconcileable?

The standard spelling in all forms of English is reconcilable.

red shift or redshift?

redshift

repellant or repellent?

The spelling repellent is preferred for nouns and adjectives in both British and American English. The alternative spelling repellant is more likely to appear in US English, though it remains a less common form. There is a belief in the US that repellant is to be preferred as a noun, but this a non-standard view. Stick to repellent for all circumstances.

resident or local resident?

Just use residents, it works in most cases. Local residents often appears as a tautology. Those who aren’t residents, are non-residents.

reveller, revelling or reveler, reveling?

In British English it is revelled, reveller and revelling and in US English it is reveled, reveler and reveling.

rigour or rigor?

British spelling is rigour and rigorous while American spelling is rigor and rigorous.

at risk

Be aware that the term at risk is chiefly British and is rarely used in the US. For American alternatives, consider in danger or in jeopardy.

rouble or ruble?

The British spelling is rouble and the American spelling is ruble.

round or around?

I want to travel round the world. I have so many friends around the world. Use round when you mean a direction of movement, and use around in the surrounded sense. I am surrounded by women, there are women all around me. Americans only tend to use around for everything.

Royal Mint

OK, so this one isn't necessarily a question of English usage as such, but just to point out that the Royal Mint makes coins, but has nothing to do with making bank notes.