Yes, it certainly is. In most cases styles will be dictated by the theme you are using, but if your theme does not provide such styles you can add them yourself to the Custom Styles section in Armadillo's Settings tab.

To add text for the relevant sections in the Blog Navigation Links stack, try using the following snippet as a starting point.

#armadilloBlogNav #blog-archives::before { 

    content: "Archives"; 

    display: block; 

    text-decoration: underline; 

}

#armadilloBlogNav #blog-categories::before { 

    content: "Categories"; 

    display: block; 

    text-decoration: underline;

 }

#armadilloBlogNav ul.blog-tag-cloud::before { 

    content: "Tags"; 

    display: block; 

    text-decoration: underline; 

}

#armadilloBlogNav #blog-rss-feeds::before { 

    content: "RSS"; 

    display: block; 

    text-decoration: underline; 

}

Please keep in mind that we are unable to provide assistance with custom coding, and suggest posting questions to the RapidWeaver Forums for further assistance with custom styling.