Internal tags

Imported from previous forum

[ original email was from Ahmed Sako - asako@golinx.com ]
The vol 1 of the 4.3 spec indicates that "The tag numbers greater than or equal to 10000 have been reserved for internal use (within a single firm) and do not need to be registered/reserved via the FIX website".

Does this mean that these tags will be ignored by the Fix engines?