Hi,
In that little code example I sent you will see on the first line the code LIST P=18F2550,r=hex - radix=hex - meaning that any uncoded number will be treated as a hex value - so if you had movlw 16 it would be recognised as hex 0x16.
It is also quite popular for the radix=dec when 16 is simply that, but more commonly coded as .16 - the full point denoting a decimal value follows.
Even when using the Radix statement, to avoid problems its perhaps wise to always code your values accordingly 0xhex or .dec or binary b'01010101'