Tagging Glyphs
A glyph name identifies a glyph. A tag classifies it. Several glyphs can share a tag, and one glyph can carry several tags without changing its name or Unicode assignments.
This makes tags useful for relationships that do not belong in a glyph's identity: a review group, a stylistic category, or a subset used by another part of the font. FontLab provides both labels you assign and labels it calculates from the font's properties.
Custom Tags
A custom tag is a label whose meaning you define. A project might use draft, review, and approved to identify stages of work, or a label such as narrowForms for a design-specific group. FontLab does not infer a workflow from those example names; the meaning belongs to the project.
Use simple ASCII letters and digits for ordinary custom tags. Spaces separate tags rather than belonging inside one tag name. Keep tag spelling and capitalization consistent.
A single glyph
- Select one glyph in the Font window.
- Open the Glyph panel through Window > Panels > Glyph.
- In its Tags field, enter the tags you want, separated by spaces or commas. Retain any existing tags you still need.
- Move focus out of the field to apply the change.
For a single-glyph edit, the field describes that glyph's custom tag set. Removing a label from the field and committing removes that custom tag from the glyph.
The Glyph window's Property Bar includes a Tags field; the Font window's Tags button offers another route to the current glyph's tags. Its small editor includes Remove all tags and Add virtual tags controls. Removing all tags clears the custom assignments; it does not disable the properties from which FontLab computes virtual tags. Adding virtual tag names to editable text does not turn the computed classification system into an editable one.
The Font window’s Tags editor lets you edit the current glyph’s tags.
Several glyphs
With several glyphs selected, use the Glyph panel. Its Tags field can display the union of their tags: a tag appearing there may belong to only some of the selected glyphs.
Use explicit add and remove notation for predictable changes across that selection:
| Entry | Multi-selection operation |
|---|---|
+review |
Adds review to every selected glyph that lacks it |
-review |
Removes review from selected glyphs that carry it |
Keep existing text and add the operation as a separate token, then move focus out of the field. Inspect a few individual glyphs afterward when the selection contained different tag sets.
The plus prefix matters when a tag is already present on some selected glyphs: simply leaving that tag in the combined display does not necessarily assign it to the rest. Similarly, deleting a tag's text from a multi-selection display is not the documented substitute for an explicit removal operation.
This add/remove notation is for the multi-selection workflow. When editing one glyph, change that glyph's actual tag list rather than treating -review as an independent command.
Tags with application-defined meaning
Some tag names have a defined effect. noexport keeps a glyph in the editable source while marking it for exclusion from output. The Glyph panel's export control adds or removes this tag. It supports subsetting without deleting work and keeps helper or building-block glyphs out of the delivered font. See Building Glyphs from Element References and The Export Process.
That is different from deleting a glyph. The drawing remains available for development, but producing a valid output font also depends on how the export handles references to it. Check feature code, classes, and any construction dependencies when excluding glyphs; the tag alone is not evidence that every reference has been resolved.
Tags beginning with a tilde, ~, belong to conditional-substitution workflows for variable fonts. They are not ordinary project labels with an arbitrary decorative prefix. Their syntax is taught in Beyond the Uniform Blend.
Virtual Tags
A virtual tag is a read-only classification FontLab derives from properties of a glyph. You cannot remove it as a custom tag; it follows the underlying property. You do not remove the classification by deleting a custom label with the same spelling. It changes when the underlying glyph data changes and FontLab refreshes the classification.
There are three broad kinds:
| Kind | Examples and purpose |
|---|---|
| Character and linguistic properties | uc, lc, and fig identify uppercase, lowercase, and figure-related groups; asc and desc classify relevant ascender and descender forms; four-letter script tags such as latn and cyrl identify writing systems; ALL supplies the broad all-glyph group |
| Construction properties | blank, noblank, composite, auto, color, image, and svg describe relevant content or construction |
| OpenType glyph definition | otnone, otsimp, otliga, otmark, and otcomp reflect the glyph's declared classification |
The labels describe different kinds of evidence. A character-derived classification comes from identity information, not an examination of whether an outline visually resembles an uppercase letter. A construction classification can depend on content across the glyph's designs, rather than only the image currently visible in one cell.
The Classes panel provides access to virtual tag groups and their members. If a property-based group appears out of date after structural changes, Font > Update Glyphs requests a refresh. Inspect the underlying glyph information if the refreshed group still differs from your expectation.
Using Tags
Tags can turn a collection you repeatedly need into something you can find again. The Font window Sidebar exposes tag-related groups, and the Classes panel can display a tag's members. Use the Classes panel's Select control for a tag to select its members. This prepares the group for a later operation without manually reconstructing the selection.
A tag can also define the intended scope of another font property. A font guideline, a stem definition, or an alignment zone may be relevant only to a particular subset of glyphs. For example, lc can restrict a lowercase guide and uc an uppercase stem reference. A shared tag gives that subset a name. Assigning the tag does not create a guide or definition. Set the relevant guide, stem, or zone to use that tag when you want to restrict it to the group; see Rulers, Guides, and Power Guides and Alignment Zones and Standard Stems.
Custom and virtual tags can also supply groups used by OpenType feature code. That connection requires the appropriate class-inclusion and feature setup, covered in Glyph Classes. It is not a promise that every custom label automatically becomes an exported feature.
Choose tag names that describe a stable purpose, and check group membership before applying a batch operation. The tag supplies a reusable selection criterion; the operation determines what happens to the matching glyphs.