Changing some text on the homepage
To see the localized files, open your file manager and go to the following location:
<your geonetwork installation directory>\web\loc\
For each available language, you will find a two letter coded folder containing an image and an xml folder.

Open the strings.xml file in a text or XML editor. The strings.xml file contains most of the generic user interface text. Other files contain strings related to error messages, to metadata standards and some other stuff.
The structure of the files is relatively simple; each element has a logical name, e.g. <admin>, and contains the string to appear in the user interface. Logically, the \en\xml folder should contain XML files with English strings, while the fr folder should contain the same XML files, but now containing French strings and so on :-)
A nice feature of GeoNetwork opensource is that is has a default language, set to English. When viewing the website in another language, all strings that are not translated will be displayed in the default language. This ensures that no text disappears from the GUI.
Browse down through the file. You will run into e.g. the disclaimer1 and 2, header_meta and main_page elements.
When deploying GeoNetwork opensource on a corporate server, you will want to make sure these elements contain text that make sense to your organization. For now, we will only change some text in the main_page1 element.
Note that the structure of the XML file is very simple. The file starts with a root element, followed by elements containing strings. Elements can also contain HTML code or can contain attributes
Replace the HTML code inside the main_page1 element with something else. You can use the following if you want:
<H1>My GeoNetwork opensource node</H1>
<P>Use this node to find spatial data in the fisheries domain.</p>
Save the file and restart your Jetty server. The GeoNetwork opensource application has to by restarted for the changes to become visible
When re-started, open the GeoNetwork application in your web browser
You can further customize the GUI by adding new elements with text and changing the XSL stylesheets responsible for the page rendering, i.e. the main-page.xsl