Thank you Petra, while searching the Web, I did find the page you point to but, from reading it, I could not gather conclusively which boxes, shapes, hues or items are actually considered the rare ones.
I mean, for example, the page
https://wiki.stratics.com/index.php?title=UO:Rares_Collection:_Gift_Boxes:_Square has a Chart titled "Chart of Rare hues" but, it lists a whole lot of hues that should be rare because listed by the MD and BT lists...
How come that so many different hues are "rare" for the square boxes ? I counted, in between the MD and BT lists shown in that Chart, about 92 supposedly "rare" hues for the 2003-2008 square boxes out of the 229 hues listed on that Chart.
Is it possible that there are so many "rare" boxes for those Years ? Almost half of the hues for the 2003-2008 square boxes are rare ones ?
Then, the newer Boxes styles at
https://wiki.stratics.com/index.php?title=UO:Rares_Collection:_Gift_Boxes:_Newer_Styles go from 2008 to 2019 (what about past that Year ?) and the text at least to my understanding, only mentions the "angel" style boxes to be as a rare one and then indicates that "certain rare hues" were used each Year but I could not find which these rare hues were, depending on the Year.
Bottom line is, from reading the Link you pointed out to, which I had found when searching the Web for rare Holiday Gifts, I could not conclusively understand, per evey Year of Holiday Gifts, which items, hues or shapes were to be considered as the rare ones for that Year's Hoiday Gifts (other then the Angel Style box for a few Years that it was available).
To be perfectly truthful I neither know nor care which boxes are rare.
The reason for me to need to find this info out, is that I am in need to make room and, therefore, to get rid of some of these Holiday Gifts by turning them in for the Clean Up Britannia points.
But should I have some rare Holiday Gifts, why should I turn them out for points while these Holiday items could be of interest to some other fellow UO player for their collection of rares ?
I would destroy, out of ignorance, rares that some other player could be happy to have (and me to enjoy the gold received in trade by spending it on something which I might need to better enjoy the game) just because the information about what Holiday Items are rare is not easily and readily available for every Year that they were awarded ?