The following mods are used by some members. They are not mandatory by any means, but you're free to use them as you see fit. In our missions, we don't use the "Require Pure Client" option, but instead trust our members to not use mods that provide unrealistic cheat-like features.
Mini Dot Labels
Generally, we technically allow labels on our missions but expect participants to manually turn them off (Left Shift + F10). Since it can be unrealistically difficult to spot other aircraft in DCS depending on your hardware (screen size, resolution, graphics settings and so on), we allow labels to be turned on if (and only if) you're using this mod. It will render tiny dark gray dots on aircraft within a certain distance. In the top line of the included Labels.lua file, you can set the size of the dot. 12 is usually good, providing a 1 pixel size dot, but on small screens with very high resolution 15 can be required. Set it as small as possible as long as you can see other aircraft at 5-10 nautical miles if you know the general direction where to look.
Download: Mini Dot Labels
Please remember that event organizers are free to disable labels completely. Also, when playing on public servers like Red Sands, labels are typically not allowed. So don't get too comfortable relying on this mod.