Hi Nicolas

Thanks for posting in the community. Please check out the supported markup section of our UML help center article for documentation on what markup can be used in Lucidchart. Hope this helps!

Also @tate s  PlantUML is  a well known markup language for UMl and I think it would be awesome if your toolsets would simply support PlantUML instead of starting your own markup language. I vote for PlantUML support in the future :)

We’re very interested in your feedback and committed to continually improving our products. If you’re willing to share, we’d love to hear more details about your use case or what you’d like to see in this experience posted in the Product Feedback section of the community - from here, other users can upvote it and add details of their own.

For more information on how Lucid manages feedback via this community, take a look at this post.