Worked on the dotnet/csharpstandard repository to improve documentation clarity around nullable reference types. Addressed a subtle but impactful issue by correcting a misplaced quotation mark in the types.md file, ensuring the definition of non-nullable reference types accurately reflects the intended language semantics. This change, implemented using Markdown and managed through Git workflows, enhanced the onboarding experience for developers by reducing potential confusion and aligning the documentation with the official C# specification. The update was delivered as a focused, low-risk commit with clear traceability, demonstrating attention to detail and effective collaboration within documentation processes for language standards.