What is the difference between dfdl:textNumberPattern="0,000" and dfdl:textNumberPattern="#,###"

[Costello, Roger L.]

Hello DFDL community,

It appears from Table 32 in the DFDL specification that # and 0 denote the same 
thing; namely they both denote a digit (0 - 9). Yes?

If so, is there any difference between these:

dfdl:textNumberPattern="0,000"

dfdl:textNumberPattern="#,###"

/Roger