Adding a condition or exception to a statement; 'however', 'provided that', 'but only if'.
The grammar point A。ただしB is used to add a condition or exception to a previous statement. It can be translated to 'however', 'provided that', or 'but only if' in English. This structure consists of two parts: A (statement) and B (condition/exception). The word ただし is used to connect these two parts.