Is it possible to define a measure with BI = user (like the measure "locsecurityusr")?

Hi all,

     I need to manage a text measure (defined at item level) that buyers can use to take notes related to their decision on buying.

This measure cannot be defined only at item level, otherwise every buyer will overwrite this measure with his/her notes.

Viceversa, it cannot be defined at any other level (e item store) because it becomes useless and redundant.

Is it possible (without the introduction of new hierarchies) to define a measure specifically for each user like the "locsecurityusr" measure (having, for example the BI = user_item)?

In this way, each user will plan the own set of data without having the risk that the values are overwritten.