Steve North

Display custom admin notices in your WordPress admin dashboard with native WordPress styling. 
Choose between success, warning, error or neutral styles.
This is a super lightweight plugin that is only loaded on your admin dashboard.

Custom Admin Notice

Does what it says on the tin

Custom admin notices for your WordPress admin dashboard. Display a custom notice to all users in your WordPress dashboard.

Poly Plugins

Giving your customers relevant information when you have sales, inventory problems, or important information related to the category your customers are browsing is made easy with Product Categories for WooCommerce.
Free Version:
<ul>
<li>Target multiple categories</li>
<li>Allows a, em, strong, and span html tags</li>
</ul>
<a href="https://www.polyplugins.com/product/category-enhancements-for-woocommerce/" title="Category Enhancements for WooCommerce Pro by Poly Plugins" rel="nofollow ugc">Enhanced Version</a>:
<ul>
<li>Add multiple notices to specified categories</li>
<li>Add notices to products in specific categories</li>
<li>Prevent checkout in specified categories based on state</li>
<li>Modify category prices</li>
<li>Wysiwig editor (Coming Soon)</li>
</ul>

Category Notices for WooCommerce

Easily display notices on WooCommerce category pages you specify. Give your customers information on sales, stock issues, news, and more.

Custom Admin Notice vs Category Notices for WooCommerce