BY CLG means a credit by clearing: a cheque you deposited has been cleared and the money credited to your account. CLG is short for clearing, and on statements that use them, BY starts a credit and TO starts a debit.
How a cheque clears
Cheques clear through NPCI's Cheque Truncation System: the bank you deposit the cheque with sends an image of it electronically to the cheque writer's bank, instead of the paper.
TO CLG
On statements that use BY and TO, a cheque you wrote that has been paid out of your account shows as TO CLG.
Example lines
Made-up lines in the usual shape. Your bank's wording will differ.
BY CLG 100001 EXAMPLE PAYERA cheque you deposited, now credited.TO CLG 100002 EXAMPLE PAYEEA cheque you wrote, now paid.
How Fynora reads it
When CLG, BY CLG or CHQ starts a line on a bank account statement you import, Fynora counts the payment as "Cheque" in the How you paid section of Reports.