 Often, Bolos on garrison duty are described as older surplus or reserve units on loan, in which case their three-letter prefix is changed to "SOL".Bolos are generally deployed in groups to provide fire support, though individual units are occasionally detached to perform garrison duty—later marks of Bolo are considered to be so capable that a single unit can be assigned to guard an entire planet, even during periods when a human commander is not available.When deployed by the Dinochrome Brigade for major combat operations, Bolos usually serve with "Planetary Siege Regiments."