Question about prayer flags

[Thrance]

From my understanding, the images/words on them are the preset prayers, and when the wind hits em, it carries said prayers across the world. If wrong, please inform me otherwise! But the question I have is, is there a way to add to it? Not so much as in adding your own flag to the set or adding to a pre-exsisiting flag, but upon hanging, dedicating/praying for other stuff as well. Is this acceptable? Is there a ritual to do this if so?

I guess an example would be, while hanging a set, also asking that say...more clean water comes to those who need it, or in a more direct personal level, Mr. X heals properly from some wound etc.

Are the prayers set and adding to em a big no no, or allowable in regards to that tradition?

Thanks in advance  

[Thrance]

Still very curious about this, I have looked around and really found no info aside from the preset prayers on the flags. I suppose because of that, a new set of flags would have to be produced, or added to an exsisting string? The reason for this post is, I have a small set that came in the mail, I want to hang them, but the notion poped into my head that before doing so, perhaps I should ask others if they have anything they would like to add to it.  

[summa crusta]

I don't know if this will help but i found a few sites about prayer flags.
http://www.prayerflags.com/
http://www.prayerflags.com/download/article.pdf

I did a search for prayer flags on http://www.buddhanet.net/ and it gave me some links. One was
http://www.buddhanet.net/ftp04.htm

I hope these links are helpful