Mike, you really do make some assumptions and statements that are baseless. Never have I said one needs to 'encrypt' the pinout, but have merely suggested that there is no 'perfect' connection and that there are other possibilities. When running 4 bit mode, one uses DB4..7 on the lcd - now, how do you connect that in a 'perfect' way to the mcu? Do you connect it to P1.0..3? or P1.4..7? And how about the order of the control signals? Say if you want to use the analog comparator on the '2051. Quickly, our concept of perfection quickly fades and reality takes over. You mention in another post that you like to be 'flexible' - have I not proposed a flexible way of dealing with imperfection? And I have posted code for such a solution. According to your criteria, I've created a positive outcome.

Using the term 'encrypt' is probably the wrong use of the word - Asif Ali used it mistakenly. To say we are deliberately 'encrypting' the data is false - just the way it finds its way out the port pins to the LCD module may not be numerically sequential - where is it written in stone that it needs to be?

Similarly for pcb layout - many times I've seen the data lines out of order and the address lines reversed so that it makes the pcb layout simpler - especially with the 8051's and jedec standard memories. You just have to choose your poison.