Accurate communication is facilitated by attaching the intended meanings to specific terms. Symantic misunderstandings result in mis-communication. Hopefully, the manner in which I am using the following terms is within the realm of acceptability to others who may be reading this. If not, then please bear with me, as the important thing is the CONCEPT, not symantics.

Generally speaking, the term "dom" is used to describe someone who's interest lies in psychological domination. Likewise, the term "sub" refers to someone who likes to be psychologically dominated. The terms "top" and "bottom" would more appropriately be applied to those who are less interested in psychological domination and more interested in the sensual/physical aspects of play. More players within the realm of "corporal punishment/spanking" play as "top/bottom", and within the BDSM community at large, more players are in "dom/sub" relationships. Thus, as a switch, I like to "top/bottom" and would prefer a partner who also prefers to "top/bottom", since I do not enjoy psychological domination.

I would like to make one further distinction, for which I do not have a precise set of terms. Within the realm of doms and tops, will be found an orientation to play, the range of which can best be described as follows:
Picture a scale of 1 to 5, where 1 = someone who's interest lies primarily in pleasing his partner, and 5 = someone who's interest lies in pleasing himself, doing what he wants with his partner, with little concern for what his partner wishes to receive. In the extreme, a "5" will purposely withhold play techniques that his partner wishes or expects to receive. Generally speaking, more "doms" will be near the 5 end of this spectrum, and more "tops" will be near the 1 end of this spectrum.

As for the sub/bottom, set up the same scale of 1 through 5, where 1 = someone who is very particular about what he/she likes and dislikes, and expects the dom or top to play according to these expectations; and 5 = someone who only wants to please the dom/top, and only wants what the dom wishes to deliver. A "5" plays only for the pleasure of the dom/top. A "1" plays for his/her personal pleasure and expects the dom/top to adhere to specified likes and dislikes. Generally speaking more "subs" will be near the 5 end of this spectrum, and more "bottoms" will be near the 1 end of this spectrum. Suffice it to say that, as a switch, my interests and expectations would put me near the low end of this spectrum; 1 or 2, both as top and as bottom. A compatible partner for me would also fall within the low end of this range; 1 or 2.

It is important to consider these differences in play orientation, as compatibility is crucial for an enjoyable experience. You must clearly have in mind what you want, expect, and enjoy within these spectrums so you are cognizant of what type of play partner you would and would not be compatible with. For instance, a dom who is a 5 and a sub who is a 1 would be perfectly miserable together; total incompatibility.