Suspect areas should be tested. If they react, the test is proof that chlorides are involved: see the comments above on silver nitrate testing and sampling.
"Stained by an unidentifiable powder"
These powders are often hygroscopic and contain chemicals which can be aggressive to steel surfaces. The colour of the powder may be mentioned. Surveyors should endeavour to take and retain samples of the powder.
"Rust streaked"; "evidence of contact with free moisture - drip down rust streaks"
These clauses will apply mainly to the packing of wrapped material; they are very important as drifting free moisture can penetrate the overlaps of packing and contact the contents so causing damage direct by contact, also creating internal sweating of the material.
NB. Where wrapped goods are concerned many of the above mentioned clauses can be used; for example, "Wrappers Rust Stained." Where galvanised material is concerned the rust is referred to either as "White Oxidation Marks" or, when more advanced, as "White Rust". It is important to mention drip down moisture runs when these are observed.
Mechanical (handling) damages
Although at the time of loading these damages may be nothing more than irregularities, they can eventually lead to damage developing and the goods must be considered as not being altogether suitable perhaps for stowage purposes, or capable of withstanding normal handling; the following clauses on Bills of Lading should make this clear.