A wise man had once told me 'in today's world it's not always important what you do, but what you can prove for others to see.' While mountaineering is an ethical sport where much is believed from the climbers and summiteers without the need of any proof whatsoever and I personally don't necessarily subscribe in the wisdom of the aforementioned wise man, it has now become more necessary than ever before to understand how to prove your ascent conclusively to an independent body that you had indeed climbed a peak and it is not a false claim; either intentionally or non-intentionally.
These days when we are more concerned about media and publicity and setting of records than the pure pleasure of climbing for your own sake, the mountaineering world at large has become more competitive and fierce in claiming and proving ascents. Record books are more important than anything personal or spiritual that a climber and adventurer should ideally gain. Therefore it is more important in the contemporary concept to understand clearly how one should go about chronicling and maintaining a record of one's ascent; more so in the case of a first ascent / new route / extremely difficult and challenging routes, etc where the outside world would be more curious about your claim and would do everything possible within their capacity to nullify your claim and sully you in the process.
In recent years in the Indian Himalaya we have the famous case of the first ascent of the extremely difficult and technical peak of Mt Gaya; where the rightful claimants of the first ascent was not accepted by the Indian Mountaineering Foundation since they could not bring back adequate proof of the ascent. The team that followed them to the summit few years later, actually found evidence of the first ascent and therefore proved that the earlier team had indeed made the first ascent.
I am going to list down few check of lists that every mountaineer should adhere to or take as a guideline while climbing a peak that would assist you in brining back adequate proofs of your ascent.
1. This is obvious but you would be surprised at the number of climbers who forget to do adequate homework. You must know the mountain and the peak you are going to attempt inside out or at least everything that is humanly possible to know. I know of even veteran climbers who after having summitted the peak realize that they had climbed the wrong peak.
2. You must always carry an adequately large scale map of the area and the mountain, so that the neighboring peaks and landmarks are clearly visible and discernable on the map. Anything of 1:50000 or larger is recommended. Carry a trustworthy prismatic compass and altimeter, previous photos of the mountains (from different directions and angles if possible), cameras and a GPS (only as a supplement and not as the first line of proof, since GPS readings can be manipulated). After getting all these, please learn to use them well and learn map reading in the classical way and to take bearings etc. Having the tools is useless if you can't use them properly.
3. You must ensure that all your team members know how to record and use the tools.
4. Submit photos of all the camp sites (include reference points and true bearings from conspicuous landmarks, also GPS positions (include errors). Submit photos of the route taken, especially of the points where the landscapes change significantly.
5. From the summit / highest point reached, record photos in all directions, showing all the main ridges and faces with part of the summit in the foreground. Also capture the neighboring summits in the same frame to show the exact orientation of the pictures. Mark each photo with the directions and bearings. Only a group of climbers waving flag on a cloudy and obfuscated summit is of no use.
6. All through the climb, record the rate of ascent and the gradient of the ground on an hourly basis and also for coming down. This is a very important factor for proving your ascent. Record rest periods as well and mention what you did during the rest periods.
7. Make a sketch from the summit showing the bearings of the major peaks in the vicinity that are clearly identified.
8. A written narrative of day to day climb is very important. Mention any conspicuous features en route and of all the camp sites, especially of the summit camp.
9. Mark the route by a marker pen on an enlarged photo of the mountain showing the face and ridge used for the climb along with the position of each camp site. Mark the altitudes of each camp site.
10. For all directions, use true compass bearing, rather than any direction relative to the climbers.
11. A very important point to remember while referring to any face or ridge is that all the faces and ridges are in the direction with reference to the summit and not to the observer. So the face of the mountain that is to your true north is actually the south face of the mountain.
12. In your ascent report avoid flowery language or ambiguity. Keep it simple and to the point, don't glorify your achievements or of any individual. Just bare and simple, what you did is all that is needed.
13. And finally be ready to accept that you may have made an error while reporting or while making the actual ascent. Don't be dogged to prove that you were indeed at a place. It really doesn't matter, like I said earlier, climbing is a journey within and you could summit Mt Everest 20 times and not tell anyone about it.