Non-Woolen Tallitot - DeOrayta or DeRabbanan?

About this learning series

Parashath Noah, Laws of Ziziyoth, Page 11: We will IY"H break up this entry over several days.

1. (continued) The second class of tallith includes those made of any sort of material, such as cotton, silk, {or canvas}.  There is a difference of opinion amongst the Authorities as to whether a tallith of this sort requires ziziyoth mi-diOraitha, or whether it is only mi-deRabbanan {i.e. a ruling intended to ensure that nobody should ever make the mistake of assuming that, since a tallith of some other material does not require ziziyoth, neither does a woolen tallith}.  Nevertheless, even according to those Authorities who say that it is only mideRabbanan, a berachah may still be recited over such a tallith, just as over all mizwoth deRabbanan.

This learning should be in memory of Maran, HaRav HaGaon Ovadia Yosef, ztz'l.