This is the standard FamilySearch citiation format.
For example:
"United States Census, 1870", , FamilySearch (https://www.familysearch.org/ark:/61903/1:1:MXWM-2ZG : Tue Mar 05 08:50:20 UTC 2024), Entry for Lee Triplett and Rhoda Triplett, 1870.
When reformatted by WikiTree Sourcer, it becomes:
* '''1870 Census''': "United States Census, 1870"<br/>citing Page: 25; Affiliate Name: The U.S. National Archives and Records Administration (NARA); Affiliate Publication Number: M593; Line: 15; Digital film/folder number: 004269312_002_M9CF-1FH; FHL microfilm: 000545960; Image number: 45; Packet letter: A; Indexing batch: N01517-8<br/>{{FamilySearch Record|MXWM-2ZG}} (accessed 17 April 2024)<br/>{{FamilySearch Image|S3HT-DTGS-GPD}}<br/>Lee Triplett (25) head of household in Floyd, Kentucky, United States. Born in Kentucky.
You can see that the two commas stand for missing information, as also seen in their Findagrave index citations,
"Find a Grave Index," database, FamilySearch (https://www.familysearch.org/ark:/61903/1:1:QV2G-7R2G : 10 June 2020), Lee Triplett, 1929; Burial, , ; citing record ID , Find a Grave, http://www.findagrave.com.