The Guild of Messengers is one of the few guilds/ orders accepted in every civilized and many near civilized lands. The Messengers know only their own special language and script (though they might know how to speak A dozen or so languages, they are prohibited to be literate in any other tongue). They are the tool of civilization, allowing for communication to be passed across the world (and the occasional small item as well).
The Guild of Messengers are known for their distinctive red caps. (They are tooks, pointed knit caps). In fact, it is against the law to wear such a cap if you are not a guildsmen on duty (the penalty being death or the loss of both legs, so most people do not risk it). They are also known for wearing huge boots (with cleated treads) and leather vests with many long pockets (where messages are kept). While they are on duty, they are wearing their cap, otherwise it is tucked in their belt or on their vest.
While on a delivery, Guildsmen are immune to detainment and all trespassing laws (though if they commit some crime, usually a noble or guardsmen follows them until they finally deliver their message). Those harming a Red cap while they are on duty is a huge offense (usually merely death, but it is more creative in some places). If the Red cap is going to give some bad new or in a potentially dangerous place, they are given an extra message that has to be delivered after that… so they can be off their way and safe from harm. If a recipient is beyond the law and harms a Red cap, then any messages sent to them are \“lost\” and that person can send out no messages.
Red Caps tend to be master runners of great endurance, acobatically skilled (able to leap and tumble over walls, gullies, etc), some skill with a horse, skill with a sling (vs animals), versed in several languages, and have memory training allowing them to recite messages and know every road and byway in a region.
More urban Red Caps are masters of Pakour or Urban Freestyle… the art of leaping and bouncing over obsticles.
Red Caps are starting to do money transfer. You deposit money and a small fee at one Guild Station and a messenger with a guild certified message travels to the person receiving the money elsewhere in the world. The messenger then accompanies the recipient to the local Guild Station, where they receive a payout.