The easy way to make sure that you are properly formatting the category name is to use URL Method 1 from the Pligg config > SEO page. This will print a url like the one below when you navigate to a category page:
/upcoming.php?category=Tech-News
Copy the part after the = sign for the proper category name to use in the code below.

This code will display the word "Test" on the "Tech News" category page on my example site:
Code:
{if $request_category eq "Tech-News"}Test{/if}
This code will display the word "Test" on the "Tech News" AND "World News" categories on my example site:
Code:
{if $request_category eq "Tech-News" || $request_category eq "World-News"}Test{/if}
If you want to add content to ALL CATEGORIES, but not the Upcoming and Published sections you can use the following code to apply the word "Test" to every category page on your site:
Code:
{if $request_category}Test{/if}