This is the tracking issue for planned breaking changes to AE2s API in 1.19.

• Rename PREVIEW_REGULAR and PREVIEW_LARGE_FONT in appeng.api.stacks.AmountFormat to SLOT and SLOT_LARGE_FONT to better communicate that they format amounts intended to fit into a standard slot
• Consider using service loader more to make it easier for addons (they currently have to test stuff like "Is JEI loaded" for adding their own JEI type converters)
• #6298.

Get you the line for me ? I've don't found Preview regular and preview large font in amountformat.class.