Augusto, You can find the documentation at: http://support.sas.com/documentation/cdl/en/lrdict/64316/HTML/default/viewer.htm#a002291852.htm http://support.sas.com/documentation/cdl/en/lrdict/64316/HTML/default/viewer.htm#a003288497.htm Looking at the statement, from left to right, indicates the following (although realize that I, too, am just learning these functions, thus my terminology may not be correct): the "s/whatever/ is indicating s/ that the definition of what we want to find follows ^ that we are only looking at the start of the string 0+ for any number of zeros at the start of the string / that the above represents what we are looking for // that we want the part of the string we defined to be replaced with nothing (i.e., removed) Thus, all it is doing is removing any zeros that may exist at the start of the string.
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