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Glyph Tags and Classes»

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Glyph Tags»

Glyph tags help to organize your glyphs into groups. You can assign multiple tags (text labels) to your glyphs, then assign the same tags to font guidelines, stems and zones, and they’ll only appear in the tagged glyphs.

Custom glyph tags»

To add a new custom glyph tag, open the glyph and assign the tag using the Tag button in the Property bar or open the Classes panel and use the + button:

Please see Classes panel for details on using it.

Virtual tags»

FontLab automatically assigns special predefined tags to glyphs whenever it updates the font. They are called virtual tags.

Tag Description
ALL all glyphs in the font except .notdef
blank no master contains an element, glyph is blank (non-printing)
noblank at least one master contains at least one element
composite at least one master contains at least one component
noncomposite no master contains a component
compound at least one master contains a glyph filter: Fill, Smart Corner, Power Brush, Glue
references at least one master contains element reference or source of a component
auto at least one master is built automatically as auto layer
color at least one master contains an element with non-default color or stroke
image at least one master contains a bitmap image
svg at least one master contains an SVG image
fig figure (numeral)
uc uppercase letter
Tos uppercase with top overshoot
Bos uppercase with bottom overshoot
tos lowercase with top overshoot
bos lowercase with bottom overshoot
lc lowercase letter
asc lowercase letter with ascender
desc lowercase letter with descender
otnone glyph with the OT Glyph Definition Class: None
otsimp glyph with the OT Glyph Definition Class: Simple
otliga glyph with the OT Glyph Definition Class: Ligature
otmark glyph with the OT Glyph Definition Class: Mark
otnone glyph with the OT Glyph Definition Class: Component
latn Latin letter
cyrl Cyrillic letter
grek Greek letter
zzzz Unknown or Private Unicode codepoint
4-letter script Letter that belongs to a particular script with this 4-letter tag

For example,

  1. Open one glyph for editing.
  2. Add the horizontal font guideline by dragging it out from the top Ruler.
  3. Select the created guideline and click the Tag button in the Property bar.
  4. Type fig in the tags edit box:
  5. You assigned the text tag fig to the font guideline. Now you will notice this guideline appears only in glyphs zero, one, two, etc. because they already have the virtual tag fig assigned.

All tags form groups and can be viewed in the Classes panel. Virtual tags are there as well.

To refresh virtual tags, choose Font > Update Glyphs.

Glyph Classes»

Glyph classes in FontLab are named sets of glyphs used in OpenType layout features and in OpenType class kerning. A glyph class may contain only one single glyph. In this case it is called a singleton glyph class.
When you rename glyphs with the Glyph > Rename Glyph menu command you can choose whether or not to rename glyph names appearing in the OT features and/or in kerning. Usually you will want to do so.

Glyph classes are created and managed in the Classes panel. You can add new, edit, rename and delete classes there. After your OpenType features using classes are ready for compile FontLab copies your classes definitions from the Classes panel to the PREFIX section of the Features panel. Glyph classes are used in compiling the OpenType GSUB and GPOS tables.

FontLab distinguishes between the OpenType classes used for OpenType layout features and the kerning classes. Kerning classes additionally are tagged as to whether they are for 1st or 2nd glyph. OpenType classes are defined once per font, and the order of the glyphs inside these classes is important. Kerning classes are defined per master, but when instances or variable fonts are exported, classes from the main master are used (you can set the main master in Font Info > Masters using the blue radio button). To ensure that you have the same kerning classes in all your masters, visit each master and use the “hamburger” menu of the Classes panel to Import Classes, picking the main master each time.

Note: One glyph cannot belong to two kerning classes of the same side.