Each French Infantry Battalion had a Piquet Company; permanently assigned to the Company was a Captain, a lieutenant, a second-lieutenant, and a couple of NCO's; all others who were assigned to the Piquet Company was on an temporary basis, usually only for a day or two. In theory each fusilier battalion was responsible for providing 3 to 5 soldiers every day for duty with the Piquet Company. After the term or assignment was up those temporally attached tot he Piquet Companies would be replaced by new soldiers from their permanent fusilier battalions.
In Europe the Piquet Companies were responsible for guarding the camp, providing advanced and rear guard on the March, protecting the Colors, Sentries and various other similar duties. Those assigned to the Piquet Company were exempted from many of the daily duties of the other members of the Battalion, including camp construction, presenting arms, and the like.
In North America soldiers assigned to Piquet Companies were often assigned on a more permanent basis as the use of Piquet Companies was more widespread and strategic rather than tactical.
Detachment of Piquet Companies occurred often as these "temporary" companies were assigned duties throughout Canada, ostensibly to protect, organize and train French Settlers and their forts from the Atlantic to the Rocky Mountains and the Gulf of Mexico. It's estimated by one historian that there were as many as 500 such detachments through New France, I am extremely skeptical at such a number because even with only 10 men assigned to each of those (5,000 total) you are looking at roughly 25% to 50% of all regulars assigned out. While their may have be 500 places that France had forces, the use of Troupes de la Marine, local Militia (Milices Canadiennes) most likely were the forces present. That's not saying the Piquet Companies were not assigned out that way, rather in much smaller numbers, maybe 20 to 30 as opposed to 500.
Another use of Piquet Companies in North America was creating rapid intervention force, along with a Corps de Cavalrie. During the Siege of Quebec Colonel Bougainville command such a force with 1,300 infantry and 200 cavalry and was assigned to watch the Western access to Quebec.
As a gamer the question becomes how does one model this.
As I am painting up Bougainville's force, I am also creating 10 companies of French Piquets, half will be treated as light infantry/skirmishes the other half in two converged battalions (one Regular, one Grenadier) it seems like the best way to model that specific force.
In addition in scenarios with Piquets I will simply be pulling figures from my Bougainville box.
But still I am not convinced I made the best choice.