It's generally recommended to use the singular form for custom post type (CPT) slugs. This is because CPTs are used to represent a single item or post, rather than a group of items.

For example, if you have a CPT for "Books," it would make more sense to use the slug "book" rather than "books." This is because each individual book post will have its own URL, rather than all of the books being grouped together on a single "books" page.

Using the singular form for CPT slugs can also help to avoid confusion and make your site's URLs more intuitive and easier to understand. However, there may be cases where it makes more sense to use the plural form for your CPT slug, depending on the specific needs of your site. Ultimately, the choice of whether to use singular or plural for your CPT slug will depend on your specific use case.

There are a few different ways to truncate multi-line text with CSS:

1. Use the text-overflow: ellipsis property: This property will truncate the text and add an ellipsis (...) to the end of the visible text. To use this property, you'll need to set the overflow property to hidden and the white-space property to nowrap. For example:

.truncate {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

2. Use the max-height and line-clamp properties: This method allows you to specify the maximum number of lines that should be displayed before truncating the text. To use this method, you'll need to set the max-height property to the maximum number of lines multiplied by the line height, and the line-clamp property to the maximum number of lines. For example:

.truncate {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

3. Use JavaScript: If you need to truncate text that is generated dynamically or based on user input, you may need to use JavaScript to truncate the text. There are a number of different ways to do this, but one common method is to split the text into an array of words, then join the words together until the text fits within a certain number of lines.

I hope these suggestions help! Let me know if you have any other questions.