Most official names for regiments are very boring and undistinguished i.e. The '52th Regiment of Foot'. You have the 4077th MASH, so I imagine in some 24th Century space-war you might have the 4,000,019th Space Marines.
Obviously, the nicknames are more popular and much more familiar. As has been mentioned, these were mostly after the person who raised them, or the name of the Colonel who commanded them. The '19th Regiment of Foot' were the Green Howards because at the time there were two Colonel Howards. One regiment wore green caps and one wore buff caps. The other became the 'buffs'. Other regiments are named after the colour of uniforms or shape and design of badges i.e. Cauliflowers.
They could be distinguished by being the King's Own, or Queen's Own or Princess' Own Regiment. Why not 'Darth Vader's Own Death Star Guards'?
They are also named for places because that was thought to be an aid to recruiting in that particular region. So the 19th Regiment of Foot is also the 1st Yorkshire North Riding. This rose to a peak in the First World War where you had the conscripted men raised from the same villages or professions or even workplaces i.e. Armoured Farmers and Coal Heavers.
So, I think you have enough room to be as creative as you wish.
Obviously, the nicknames are more popular and much more familiar. As has been mentioned, these were mostly after the person who raised them, or the name of the Colonel who commanded them. The '19th Regiment of Foot' were the Green Howards because at the time there were two Colonel Howards. One regiment wore green caps and one wore buff caps. The other became the 'buffs'. Other regiments are named after the colour of uniforms or shape and design of badges i.e. Cauliflowers.
They could be distinguished by being the King's Own, or Queen's Own or Princess' Own Regiment. Why not 'Darth Vader's Own Death Star Guards'?
They are also named for places because that was thought to be an aid to recruiting in that particular region. So the 19th Regiment of Foot is also the 1st Yorkshire North Riding. This rose to a peak in the First World War where you had the conscripted men raised from the same villages or professions or even workplaces i.e. Armoured Farmers and Coal Heavers.
So, I think you have enough room to be as creative as you wish.