Anybody know what (m/m) stands for? in relation to TLC!

[seamoro]

Here is the context
"Any spot with solution T is not more intense than the spot with the same Rf obtained with Solution R: The nitrate content 9expressed as potassium nitrate) should be no more than 1 % (m/m)"

[GregK]

mass/mass? I usually see it as w/w (weight/weight). In context, the spot from solution R represents 1% mass/mass, so the test solution T should be less intense.