It means that you can use adobe PS brushes (*.abr) in PSP X5 via the File > Import > Custom Brush option. If you have adobe PS brushes and want to try this out, you can download the trial -- http://pnoy.me/coreltrials
-- then follow these steps to import the brushes.
To import a custom brushIn Edit workspace
1. Choose File > Import > Custom Brush. The Import Custom Brush dialog box appears.
2. Click Open.
3. In the Open dialog box, navigate to the brush file that you want to import, and click Open.
4. In the Import Custom Brush dialog box, select the custom brushes that you want to import, and click Add. If you want to import multiple brushes, click Add All.
5. Click OK to import the custom brushes.