欄外

1. Origins, structure, and basic meaning

• Structure: 欄外 is read らんがい.
• Basic usage: It refers to an area outside a designated field or to the margin of a page.

2. Common pitfalls and similar expressions

• Outside a form field
  • 申込書の欄外: outside the designated entry field on an application form.
• A book margin
  • 本の欄外: the margin surrounding the main text of a book.