Visual primitive

Data labels `has_data_labels`

Numeric values placed next to bars, points, or segments.

Endpoint or per-element labels turn a chart into a self-explaining artefact. Bars with labels ($32, $40, ...) free the reader from having to read the axis. The trade-off: labels add visual noise in dense charts. Best practice in editorial work is "label what matters, not everything".

When critical

Hero charts where the takeaway depends on specific values. Sparse charts where each value is a deliberate beat (e.g., 5 bars in a hero chart).

When optional

Dense exploratory charts where the shape is the story (scatter, dense lines).

Failures when missing

reader has to round-trip to the axis for every value
specific takeaway numbers are buried in the visual

Failures when present (badly)

overcrowded (every point labelled in a 50-point scatter)
labels overlap each other or the bars

Critical for families

bar
composition
flow

Aspose property bindings

DataLabels.visibility
DataLabels.format
DataLabels.position