in carboxylic acid: Hydroxy and keto acids. ...not the same. The 2-hydroxy acids form cyclic dimeric esters (formed by the esterification of two molecules of the acid) called lactides, whereas the 3- and 4-hydroxy acids undergo intramolecular esterification to give cyclic esters called lactones.
VBA's ActiveWorkbook property refers to the workbook with the focus. The active workbook may or may not contain the code that's referencing the active workbook, which is an important distinction. It's perfectly acceptable to use this property to reference the active workbook from code inside the active workbook.
Accessing the Private Module of the Workbook Object (ThisWorkbook). There are at least 2 ways to gain access to the private module of the Workbook Object (ThisWorkbook). 1) While in Excel proper, right click on the Excel icon, top left next to File and choose View Code. 2) While in the VBE double click the Module called ThisWorkbook, seen in the Project Explorer (View Project Explorer (Ctrl + R)).