A B757 landing at EBBR reported a potentially confusing ATC procedure that could result in a runway incursion. The reporter recommended chart or procedural changes.

Narrative

Not certain which Tower frequency was in use. An experience I had vacating Runway 25L at Brussels leaves me feeling that an additional note should be added to the commercial chart page; or a change in Tower practices be negotiated. As I was clearing Runway 25L at C4; I received the instruction to hold short of Runway 20. That clearance was embedded into a longer clearance that I do not remember in entirely. I had not yet found the hold line for Runway 20 and I was focused upon clearing Runway 25L as my first obligation; and that hold line was in sight. What I didn't expect was that both hold lines are co-located; but in opposite directions; and the Tower was; in effect; asking me not to clear Runway 25L across its hold line. I would have to say in hindsight that the Controller was judging my speed to be slow enough to be able to accommodate. In the cockpit; we had a quick discussion about which hold line we were approaching and I balked at the clearance because I was not yet clear of Runway 25L and the First Officer transmitted something. The response was in effect the same clearance; but thankfully said a different way; 'hold your position.' I firmly applied the brakes and came to a stop with urgency that was surely felt throughout the aircraft. Somewhere in there; an air carrier flight was cleared for takeoff on Runway 20. I asked the First Officer to relay my exact concern that Tower might be about to land an aircraft behind us on Runway 25L while I was not fully clear; but when he paraphrased; the concern was not articulated. By then; the air carrier was beyond the intersection and we were cleared to cross Runway 20. After parking at the gate; I initiated a discussion with the controllers to make sure they could relate to my concerns. The discussion; which eventually took place on a telephone with a manager; revealed that the controllers also see the taxiway arrangement as a set-up for confusion; or worse. I was asked to report it at my end so that they could get a well-known trouble spot (Hotspot 3) remedied. They described the practice of holding airplanes short of Runway 20 on C4 as something they didn't like either. I was assured that; per their practices; nobody was about to land behind my on Runway 25L; a fact that would have affected my thinking if I had known when it mattered. I should have pointed out that the whole dilemma could be handled with a lot less confusion and less risk if my clearance was to cross Runway 20 on C4; holding the air carrier in position a few seconds longer. I will add that a few seconds earlier I owned Runway 25L and could have opted to clear on C5; thereby crossing Runway 20 and forcing the air carrier to hold a little longer. The best solution I could suggest for this would be getting Tower to always issue clearance to cross Runway 20 on C4 in that situation is lieu of this one I received. If not able above; say 'need not clear Runway 25L; hold short of Runway 20.' Place a note in the commercial chart warning of the potential of receiving such a clearance. The Controller I spoke with mentioned that this configuration is in use on an infrequent basis.