This string is set/defined in the "catalogbrowse.xml" and some other files (see below).
For the U.S. English language, this file is located in folder: "%USM_HOME%\view\webapps\usm\locale\icusen\request".
Do not change the out of the box delivered file. But a copy of it in stead.
The steps to be taken then are described below.
1. Copy the following files:
into "%USM_HOME%\filestore\custom\locale\icusen\request" (when not existing already, you need to create this path).
2. Open(notepad) the the copy of the files.
Change the text between the tags to the new value you would like to use:
<unknown_description>Catalog services not categorized.</unknown_description>
3. Save the changed files.
4. After saving the changes, you will need to restart the catalog service for them to take effect.
a. Stop the CA Service Catalog services(Accounting and Catalog)
b. Empty/clear the %USM_HOME%\view\translets folder
c. (re)move the %USM_HOME%\logs\*.log files
d. Clear the browser-cache
e. Start the CA Service Catalog services(Accounting and Catalog)
The breadcrum should then contain the changed folder name "Not Categorized xx" too.