If you are referring to Quik Check for Windows, the issue is related to the setting you have defined in the Company Profile.

One the second screen of the Profile (Interfaces), there are two drop-down fields that allow you to choose which information is sent to the GL subledger reference and description fields. I believe the default choice for the GL reference is the Check Number, and the default for the GL description is Post seq/Entry/Desc. The number "251-39-108" is probably referring to posting sequence 251, entry 39 and description 108.

You can edit these fields at any time, but they will not change subledger batches that have already been retrieved, nor checks that have been posted but not yet retrieved into GL. The change will only affect checks you post from now on. If it's the description yo wish, then you can choose 'Check Description' as the field for "Send to GL Description".

Regards,
Softrak Support