[...] unlike tanru, a "lujvo, like other brivla, have a fixed place structure and a single meaning, encapsulating a commonly-used tanru into a lujvo relieves the listener of the burden of creative understanding" (12.1, second paragraph after example 1.2). In other words, once something is in a lujvo, it has only one meaning. That meaning is determined by the lujvo creator. So, you COULD have meant it to mean a "dog that houses fleas", but since the example we are creating is specifically not intended to convey that, we have already constrained what the relationship between the parts will be, and hence the place structure.