uhttpd config, index file, php vs. html

From here: link

I read:

index_file	file name	no	index.html, index.htm, default.html, default.htm	Index file to use for directories, e.g. add index.php when using php
index_page	file name	no	index.html	Index file to use for directories, e.g. add index.php when using php (last, 20131015, replace index_file ?) should be noted: list index_page "index.html"

and if I put in my config file:

        # Index file to use for directories, e.g. add index.php when using php
        option index_page         'index.html'
        option index_page         'index.php'

the command uci show uhttpd tells me:

uhttpd.main.index_page=index.html index.php

infact i have a index**.php** in /sd that works! and the index**.html** in the /www that works also...the only one that doesn't work is the index.html in the /keystore_manager_example dir