I cannot find any information about a "63 Angle Modified WLL" in standard construction, engineering, or architectural literature. It's possible this is:
- A niche term or abbreviation: Specific to a particular company, project, or highly specialized field. If you can provide more context (e.g., industry, company, drawing number), I might be able to find relevant information.
- A misspelling or misremembered term: Could you double-check the spelling or provide any additional details about where you encountered this term?
- A hypothetical or fictional concept: If this is for a fictional work, I can still help you brainstorm details and descriptions, but I won't be able to provide real-world information.
To help me understand what you need, please provide more details about the context in which you encountered this term. More information is essential for me to create a helpful and accurate article.