Gliding skill levels are recognised by badges.
A and B Badge
In the UK the first step on the gliding ladder is the 'A' badge and to get this you need to complete a single successful solo flight and be able to show a grasp of the rules of the air. 'Successful' in this context means 'to the satisfaction of your instructor' but it is very unusual for anyone not to have a successful first solo - instructors are far too careful for that!
The next step is the 'B' badge and for this you need to make one soaring flight of at least 5 minutes duration. A soaring flight is where you are able to use the air currents to maintain yourself at or above the height you were launched to. In addition you need to show that you understand the rules of the air including any airspace regulations which you are likely to incur during your flying.
Clubs in the UK have slightly different rules about how they permit early solo pilots to fly but in general until you have done a dozen or so solo flights you will be required to have a check flight with an instructor every day before you fly solo. This is to make sure that you are 'on form' that day and to catch any bad habits early before they develop. It also makes sure that you are able to cope with whatever weather conditions there are that day and in some sorts of weather you will need to accept that you can't fly solo until you have had more experience. As you get more solo hours the check flight frequency will be reduced and you will be allowed to progress from the training dual-seater onto a solo machine.
The Bronze Badge
The bronze badge is the next major step after soloing and is broadly equivalent to the 'glider pilot's licence' in other countries. At this stage you will probably be keen to build your solo flying hours but it is only by flying with an instructor that you will be able to make progress towards your bronze badge. Bronze training takes you to the point where your flying is much more second-nature enabling you to fly around accurately while most of your concentration is focused on where you are going and how you can get there. It also covers a lengthy list of capabilities such as extensive stall and spin recovery and landing in confined spaces, perhaps off the airfield, which you may need some day if things go wrong.
Before you can apply for the bronze test you need to have completed 50 solo flights. To qualify for the bronze badge you need at least 3 check flights with an instructor who will exercise your flying skills fully. You also need to pass a written multiple-choice examination with papers in principles of flight, airmanship, meteorology, radio and navigation. Completion of this badge is a sign that you have really arrived as a solo glider pilot.
Up to now you will have been required to stay within gliding range of your airfield. Of course this can be quite a long way depending on what height you've been able to achieve but nevertheless you will not have been allowed to set off into the blue yonder. To do that you need to get your bronze cross-country endorsement. This is intended to demonstrate that you have acquired the skills needed to navigate across country obeying the rules of the air and making use of whatever lift you can find along the way, and if necessary to be able to pick a safe landing area and get down into it. For this endorsement you need to have done at least 2 lengthy soaring flights, one of at least 2 hours and another of at least 1 hour. You then need to plan and execute landings into off-site areas such as grass fields and plan and execute a triangular flight of at least 100 kilometres. If one is available you can use a motorglider for the last 2 tests and even a light aircraft for the navigation test since it is not your actual glider control skills which are being tested. When you have passed this endorsement you will be allowed to fly away from your own airfield as you please. (Well that's not strictly true - if you are using club aircraft you will probably still need permission from an instructor).
At this point you can if you wish start to tackle the FAI badges which are set and recognised internationally by gliding's international supervisory body, the Fédération Aéronautique Internationale (FAI). From this point on all of your badge claims will be based on solo flying, no-one will come with you for a check flight, it is entirely up to you to plan and execute the necessary tasks for each badge step. To prove that you have achieved your claim, you need to carry a logger which records your height and gps position.
The Silver Badge
You need to make at least 1 flight of 5 hours duration. You need to achieve a gain in height of 1000 metres from the lowest point of a flight. You need to make a flight outwards from the airfield of at least 50 kilometres. (The last task normally requires you to also land in a remote field.)
The 100km Diploma (UK only)
Part 1: A pre-declared flight (this is one where you say in advance what you are going to do) of at least 100 kilometres.
Part 2: A pre-declared flight of at least 100 kilometres at an average speed of at least 65 kilometres/hour.
The Gold Badge
For the gold badge you need to make at least one flight of at least five hours duration - you will normally have done this already for the silver badge. Then you need to achieve a height gain of at least 3,000 metres. (This is measured from the lowest point of your flight but whatever the circumstances you will be approaching the point where oxygen is needed). Lastly you must complete a flight of at least 300 kilometres.
Diamonds which are worn on the silver or gold badge are awarded for the following achievements:
The Height diamond for a gain of at least 5,000 metres (about 16,405 feet).
The Distance diamond for a flight of at least 500 kilometres.
The Goal diamond for a pre-declared flight of at least 300 kilometres.
It is a big achievement to gain all three diamonds. Only a few hundred people world-wide have achieved this.
There is a 750 kilometre diploma (UK only) and the FAI issues diplomas for flights of 1,000 kilometres or more in 250 kilometre increments.