Italy Revenues

As best as I can tell, these are all revenue stamps from Italy. Does anyone have other information about them (catalog #'s, dates of use, etc.)? I assume they are not listed in standard postage stamp catalogs:

Free Gift from CJD. Thank you very much.

1924
Italian Federation of Libraries
Federaz. Italiana Biblioteche Pop.

(Regular issue ...Period after "POP")



Variety (no Period after "POP")
http://www.italianstamps.co.uk/king...a/index.html

These are not revenues: they are postage stamps and were used for a short period during 1924 for the franking of the mail of organizations entitled to exemption from the payment of postage. In this way there was a better accounting of the cost of such benefit to the Treasury: they were supplied free of charge to the entitled organization and could be used only on the official mail of said organizations.
Michele

Right,
thank you Michele, I'll adjust my pages.

Hi wt1:Link too complete pic's of the sets..
http://www.filateliaitaliana.it/cat...p=2&pstart=0

Segnatasse Vaglia
Money Order
40c