I've heard of this kind of script used to communicate special "Terma" (Treasures) to Tertons (Treasure Holders). I found this sample on Facebook:
Terma revelation by Terton Migyur Dorje, written in dakini script (yellow letters outlined in orange on blue background). "Those who see this script will not experience the three lower realms and will be liberated from the fear of falling into the lower realms; will be purified of the five poisons and freed from the results of one's karma; will be freed from the fear of remaining in samsara."--terma revelation of Terton Migyur Dorje. --from the following online source
I was intrigued by the way the letters are interconnected and appear to dance across the page. I once met a woman who had a connection with the late Dudjom Rinpoche (1904-1987). One day he showed her many small pieces of thin yellow paper with "Dakini Script" which appeared as incomprehensible scribbles. The Terton is able to decipher this writing and unfold whole Teachings that were embedded from an earlier era or from another realm.
Chögyal Namkhai Norbu founder of the International Dzogchen Community is a Terton and our retreat land, Khandroling, the location of many of his Terma related to the Vajra Dance.
Here's an interesting article about another teacher of mine, Chogyam Trungpa Rinpoche's early terma which describes the yellow scrolls recovered by CTR.
As this particular page is the most frequented page on this blog, I enclose a link to the very interesting site http://www.dakiniscripts.at/dedicated to Dakini Scripts,