If you're an enterprise user you can share your custom style with your organization via the Style Manager in the Members Area of the Intelligent Editing website.
The first step is to export your custom style from PerfectIt. Click 'Manage Styles' in the PerfectIt 5 tab:
Select the style you wish to export from the 'Current style sheet' dropdown list, and click 'Export':
Choose whether you want to allow the users you share your style with to edit it or not:
Choose a filename and location, and click 'Save'.
Log in to the Members Area of the Intelligent Editing website and click on the 'Style Manager' tab:
Either click the 'Upload Style Files' button and select the style you wish to share, or drag the file into the 'Upload Style Files' area. You can upload multiple styles at a time.
Once the style has finished uploading it will appear at the bottom of the page:
From here you can set the default style for your organization – details of how to do that can be found here.
Click on the 'Installer' tab. Download either the per-machine installer or the per-user installer according to your requirements.
Unzip the downloaded folder and follow the instructions in 'Enterprise Installer Instructions for PerfectIt 5.docx' to install PerfectIt.