SOT23-5 Package vs SOT23-5L...Differences?
I believe the difference is the same as Sot23-5+, in that the 6th pin (Sot-23 can accommodate 6 regular pins) is present, but unused. Regular Sot23-5 has the 6th pin missing.

Based on looking at some other ST datasheets, Sot23-5 and Sot23-5l are used interchangeably.
http://www.st.com/web/en/resource/technical/document/datasheet/CD00176077.pdf
http://www.st.com/web/en/resource/technical/document/datasheet/CD00079372.pdf

The measurements are exactly the same in any case.

Also, you should always add the part number (AND manufacturer in this specific case) to the question.