First of all, the R51 series is not the latest R50 series model (the R52 is), so it is rather strange to see such displays on a model that is not the most recent.
Second, I made sure I had the latest tabook (May 2005), and there are NO R51 (or R52) models listed with such resolution displays.
Lastly, I checked the IBM online sales site for the R50 models, and once again such resolution displays are not listed
Here's one more: Hardware Maintenance Manual for R50/R50p/R51. I agree that it's a bit mysterious. The hardware manual mentions the UXGA and QXGA panels as replacement parts and states them as features of the R50p. The model numbers are 1823/1833-23x and 1823/1833-25x mostly. The product overview page at support.ibm.com doesn't cover those. I could imagine that those might be japanese market only again.
Ok, since the information is vague, i uncommented the two entries. Wyrfel 00:23, 31 May 2005 (CEST)