EDIT The final 7 characters The last block of the Basic Multilingual Plane contains nonprintable characters but control characters for text processing.

The last 2 characters of the BMP are «Non-Characters», they must not be used in text and even mess with this database if the thumbnail is clicked on. Come on, try it!

The second to last character is forever defined as a non-character to keep it distinguishable from the character U+FEFF, even when the bytes are switched (Little/Big Endian problem, see U+FEFF for explanation).
 
EDIT also…..................

This character, �, is what you get to represent invalid data. See U+FFFD.
 
U+FFF0 NOT ASSIGNEDU+FFF1 NOT ASSIGNEDU+FFF2 NOT ASSIGNEDU+FFF3 NOT ASSIGNEDU+FFF4 NOT ASSIGNEDU+FFF5 NOT ASSIGNEDU+FFF6 NOT ASSIGNEDU+FFF7 NOT ASSIGNEDU+FFF8 NOT ASSIGNEDU+FFF9U+FFFAU+FFFBU+FFFCU+FFFDU+FFFEU+FFFF
U+FFF0 
U+FFF1 
U+FFF2 
U+FFF3 
U+FFF4 
U+FFF5 
U+FFF6 
U+FFF7 
U+FFF8 
U+FFF9 INTERLINEAR ANNOTATION ANCHOR
U+FFFA INTERLINEAR ANNOTATION SEPARATOR
U+FFFB INTERLINEAR ANNOTATION TERMINATOR
U+FFFC OBJECT REPLACEMENT CHARACTER
U+FFFD REPLACEMENT CHARACTER
U+FFFE 
U+FFFF 
CHARACTER  < BLOCK > 
U+FFF0 – U+FFFF Specials
DEUTSCH : ENGLISH