however

1. Origins, structure, and basic meaning

• Structure: 但し, read ただし, is a connective that adds a condition or exception to what precedes it.
• Basic usage: 参加は自由です。但し、事前の申込みが必要です means participation is optional, but advance registration is required.

2. Common pitfalls and similar expressions

• Not reversing everything said before
  • 但し、一部を除く adds a restriction excluding some cases.
  • It narrows what was permitted rather than denying all of it, so the actual exception matters.
• The word for a proviso
  • 但し書き, read ただしがき, means a written condition or exception.
  • It does not necessarily mean small lettering; the focus is the added condition rather than the font size.