in the rm carreer guide its says there is sometimes the option to skip general duties and go straight to a specialisation training. how is this acheived is it something you can request? does it happen often?
If there is a need for that specialization and they lack people you may be given the option to go to specialization training, don't know how often it would happen as it would depend on how many people left the forces or changed specialization i would think.
Generally you can expect to wait up to two years to specialise unless you volunteer for a shortage category trade, currently trades such as Driver, Clerk or Chef.
You can volunteer for any trade but allocation is based on experience, aptitude, (rank for some trades) & recommends, so you may not always get what you wish if there are shortages elsewhere. You can sometimes go for more than one specialisation over the course of your career.