All the manual alphabets (called “fingeralphabets” here) that are labeled “downloadable” have been finished and approved by at least one official party.
You can read more about who approved the material and in what forms it is available beyond the free PDFs on each main country page (just go here, click on the desired flag and the link will take you there)
You are allowed to print and distribute these fingeralphabets for free in any quantities, as long as it is (and stays) non commercial. It is not allowed to charge money for this material. If in doubt – maybe because you are doing a free, but commercially motivated, marketing campaign – make sure to contact me to get the propper permission first.
If you follow this link you will find more in depth information about this Creative Commons license. Remember: A Creative Commons license does not mean something is in public domain!
If you see one of these alphabets being used for commercial purposes, also, please contact me.
Your help in making sure that this work is respected and not used for exploitation makes all the difference!