Related Rule
Australia
Practice Relating to Rule 14. Proportionality in Attack
Section C. Information required for judging proportionality in attack
Australia’s Defence Force Manual (1994) refers to the declaration made by Australia upon ratification of the 1977 Additional Protocol I to the effect that “ADF [Australian Defence Force] commanders will, by necessity, have to reach decisions on the basis of their assessment of the information available to them at the relevant time”. 
Australia, Manual on Law of Armed Conflict, Australian Defence Force Publication, Operations Series, ADFP 37 – Interim Edition, 1994, § 511.
Australia’s LOAC Manual (2006) refers to the declaration made by Australia upon ratification of the 1977 Additional Protocol I to the effect that “ADF [Australian Defence Force] commanders will, by necessity, have to reach decisions on the basis of their assessment of the information available to them at the relevant time”. 
Australia, The Manual of the Law of Armed Conflict, Australian Defence Doctrine Publication 06.4, Australian Defence Headquarters, 11 May 2006, §5.11.
The LOAC Manual (2006) replaces both the Defence Force Manual (1994) and the Commanders’ Guide (1994).
Upon ratification of the 1977 Additional Protocol I, Australia stated:
In relation to Articles 51 to 58 inclusive it is the understanding of Australia that military commanders and others responsible for planning, deciding upon, or executing attacks, necessarily have to reach their decisions on the basis of their assessment of the information from all sources, which is available to them at the relevant time. 
Australia, Declarations made upon ratification of the 1977 Additional Protocol I, 21 June 1991, § 3.