DTD Doubt??

I have a doubt in my DTD because I don't now if the [ a-dtype NMTOKENS
"Tot_por currency Total currency DataP date " ]  is in a correct format in
the follow DTD:
I want to now what is the #PCDATA format or where i can obtain more
information about it, because I can´t see in any book or site the
explanation about it!
Thanks,
Tânia Barros.

<?xml version="1.0" encoding="ASCII"?>

<!-- Elements -->
<!ELEMENT DTD_Web (Extensao+ ) >
<!ATTLIST DTD_Web
	Adress CDATA #REQUIRED
	NumID CDATA #REQUIRED >
<!ELEMENT Extensao EMPTY >
<!ATTLIST Extensao
	NIBF CDATA #REQUIRED
	Tot_por CDATA #REQUIRED
	Total CDATA #IMPLIED
	Moeda CDATA #REQUIRED
	RefP CDATA #REQUIRED
	DataP CDATA #REQUIRED
a-dtype NMTOKENS "Tot_por currency Total currency DataP date " >
<!-- General entities -->

<!-- Notations -->


------------------------------------------------------------------------
Tânia Figueiredo Barros [mailto:tania@xxxxxxx]
SIBS / MULTICERT          <http://www.sibs.multicert.com/>
Rua Soeiro Pereira Gomes, Lote 1 - 1649-031 Lisboa, Portugal
Tel: + 351 21 791 88 00      Fax: + 351 21 794 24 40


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