The CLEAN function, which predates the Unicode character set, removes the first 32 non-printing ASCII characters, and the same characters from the Unicode set.
Ọrụ CLEAN, nke na-agbaso usoro agwa Unicode, e mere iji wepu ihe odide mbụ ASCII na-abụghị akwụkwọ na-ewepụ otu ihe odide ndị ahụ sitere na Unicode.