I tried this
Options +Indexes
IndexOptions FancyIndexing VersionSort NameWidth=* HTMLTable Charset=UTF-8
HeaderName /header.html
ReadmeName /footer.html
IndexIgnore header.html footer.html .htaccess
How To Include a PHP File Site-wide Using .HTACCESS or other methods
Apply .htaccess HeaderName to all lower levels?
How To Include a PHP File Site-wide Using .HTACCESS or other methods
It just simply does not do anything. I also followed an old guide to enable Layout Header (something with mod_layout in apache) but it seems it's too old.
The best i managed to do is to show the content of my "header.html" into the directory (which is listed with Option +Indexes)
I am doing all of this in a specific folder .htaccess, not in the root .htaccess It looks like this :
Options +Indexes
IndexOptions IgnoreCase FancyIndexing FoldersFirst NameWidth=* DescriptionWidth=* SuppressHTMLPreamble HeaderName header.html
Please, help