Two things people build first. Who shot it: match on the camera body serial and fill photographer, copyright and credit, so a second camera’s frames land with the right byline and nobody types it. Where you were in the game: match on the card folder and fill a period, so folder 101 reads “before” in the caption and 102 reads “during”. One set can do both at once.

Sets live under Metadata → ExifID. A set has a name, two to six columns, and one or more ways to identify a photo. Each way is a match key: what to look at, and which columns it is allowed to fill.

Camera body serial. Identifies the camera, so it identifies the photographer holding it. The most reliable key for “who shot this”.

Camera model, camera make, lens model. Every body of that model, every camera from that maker, every frame on that lens. Useful when the distinction you need is the gear, not the person.

Card folder and Card folder contains. The DCIM folder the frame was copied out of, 103EOS_D. Canon lets you name card folders, so pregame can go in one and the match in another and each frame identifies itself. Recorded at ingest, because no camera writes it into the file and the card is gone afterwards; only photos ingested by GalleryID from 1.0.120 on carry it. The exact form wants the whole name. Contains (1.0.137 on) matches if column A appears anywhere in it, which is the one to use: cameras roll the folder from 101EOS_B to 102EOS_B and the suffix differs by body, so a row of just 101 names the period whatever the body appends, and a row of EOS_B names the body whatever the number.

Folder prefix, folder name contains, folder name (exact). The folder the file sits in now. Prefix is the text before the first space or underscore, so “101 Baseball” and “101_baseball” both read 101. Contains is for when the identifying part sits at the end of the name, where a prefix can’t reach it. These stop matching once the photos move to a folder named differently, which is why the card folder keys exist.

Original filename prefix and filename prefix (current name). The prefix the camera gave the file, kept through an ingest rename, or the prefix of whatever it is called now. Set camera 1 to AS1 and camera 2 to AS2 and each body identifies its own photographer. Easier to hand an editor than a serial number.

Name the columns. The names you give columns B to F show up on the token buttons, so the picker reads “Photographer” instead of “col B”. Two columns is the usual set; six is the most.

Each key fills what you tick. Under a key’s rows is a row of checkboxes, one per column. A key only ever writes the columns it has ticked. That is what lets one set answer two questions: the serial key fills photographer and credit, the card-folder key fills the period, and neither touches the other’s columns.

Every key that matches contributes. Keys are listed in order, and every key that matches fills its ticked columns. If two keys both fill the same column, the one higher in the list wins. This is not first-match-wins: a lower key still fills the columns the higher one left alone.

Rows. Type them, or Paste lines from a spreadsheet (tab- or comma-separated, column A first), or Import a TSV, CSV, TXT or XLSX. Import adds to the key you run it from, so a sheet of serials and a sheet of folders can each feed their own key.

Bind. In the IPTC template editor, the ExifID picker says which set {exif_b}..{exif_f} resolve against. Save to Folder binds it to that folder along with the template; Save as Default makes it the fallback for folders with no binding of their own. The picker also offers New set and Edit this set, so you never have to leave the template to fix a row.

Use. The tokens work anywhere the other tokens do: in an IPTC template field, so a caption reads {exif_b} the ball {exif_e} the game; in the ingest folder pattern and filename; in a rename pattern; in an FTP remote path. At ingest they resolve as the files are copied, so a two-photographer card lands with each frame already crediting the right person.

Nothing matched. A token resolves to nothing rather than to a placeholder, so a frame no key can identify gets a gap in the caption, never the literal text {exif_b}. If a whole folder resolves empty, the usual cause is the key: a card folder key on files that were not ingested by GalleryID, or an exact key on a name that has since changed.