[jbacelar]

I also use file_name (full) for note IDs. But, because you need to remove the extension?

To extract notes from all files and dump them in a specific file (notas.xhtml), as I have not sufficient knowledge of Python, I do the following:
1- I make notas.xhtml
2- I use this regex-function

#Searching: (<p class="nota".+?>.+?</p>)

def replace(match, number, file_name, metadata, dictionaries, data, functions, *args, **kwargs):
    notas = open('e:/Libros/Taller/En curso/notas.txt', 'a')
    texto = match.group()+'\n'  
    notas.write(texto)
    return ''
replace.file_order = 'spine'

3- I do copy-paste of notas.txt to notas.xhtml

And sorry for my english.