Amendment History of Acts Interpretation Act 1901 SEC 15
The original version of the Acts Interpretation Act 1901 2 contained no subsections for Section 15, only the following text:
15. Every Act amending another Act shall, unless contrary intention appears, be construed with such other Act and as part thereof.
This section remains unchanged. Section 15A first appeared by way of Acts Interpretation Act 1930 23 and was modified by way of Acts Interpretation Act 1937 10. Section 15A has not been modified since this time. As of January 2011, Section 15A is defined by the following text:

