Easy enough to get, although takes a day. Fill in the form, give them your passport and some cash and go back that day at 16:00 to pick it up.
See full entry for all details.Fill in this form, drop it off at the Mauritanian Embassy in Rabat in the morning (9am doors open) with:
- 340DHS (£30)
- your passport
- a copy of your passport
- two passport sized pictures
They give you a 'receipt' which you take back to the same office at 16:00 the same day and get your passport back with visa.

The form is easy enough to get hold of, but it can seem a bit much as its all in French. To be honest, they didn't even look at it; the reason I say this is because I wanted a double entry visa (ticked the box and everything) and got a single entry.
They also don't seem to care whether it's the original (single sheet, double sided) or a two sheet photocopy. There is also a photocopier available at the shop just around the corner if you need one (main road, turn left).
Get the form at the office (if there is a queue just walk to the front and ask for 'le papier'). No one will mind and then fill it in while you wait.

The questions are mostly easy, but the second page starts to ask about how many active visas you have from the last 5 years, how many countries you have visited in the last 10 years - I left these blank despite my passport having loads of visa stamps in it.
The next bit asks about if you have a Mauri sponsor. Again, leave it blank.
There is also a question about whether you have a visa for the next country...just tick no and put 'en la duane' at the border).
You want a transit visa and you are there for tourism. There are a few bits about where you will cross the border, put in Nouadhibou. Sign and copy the rest from your Moroccan green card / entry form - it's in French too.

Where you don't know, leave it blank. I did. It worked. I love pointless admin me.
Also, avoid Monday's and days after a bank holiday. Basically, applicants then build up and it turns into a nightmare. There apparently was even a punch up the day before I arrived.

Mauri Consulate in Rabat:
6 Rue Thami Lamdouar,
Souissi
Tel: 037 65 66 78
Petit Taxi from town 20DHS
...most will just know where it is, otherwise just say Soussi and watch out for very obvious signs on the right side of the big road after the city walls.

Help the others fill in the form too...and one person can make the application for a group - obviously that person should be rewarded by the others with beer or some other internationally recognised currency! :)

P.S. Advice 2: Don't get annoyed with any official personell...that said you will at least once just to get it out of the way and realise how pointless it is! I did here and it helped not a bit. Like I say, you will do it once...it's a learning curve. Anyone have any funny border / annoyance stories? Would love to hear and chuckle about them. :)