Visual primitive

Axis titles `has_axis_titles`

Labels naming each axis (units, what the axis encodes).

Without axis titles the reader has to infer units. The most common offence: a y-axis labelled "$" with no specification of millions/billions/per-unit. Editorial charts often skip them when the axis is obvious from context (e.g., dates on x-axis), but skipping the value-axis title is rarely safe.

When critical

Whenever the axis is a quantity that requires units (revenue, percentage, count). Even time axes benefit from a label when the period is non-obvious.

When optional

When the slide title implicitly states units ("Total revenue (\$M)") and the chart is in tight context.

Failures when missing

missing-label
dual-axis-omission (combo charts often hide both axis titles)
reader infers wrong units (millions vs thousands)

Failures when present (badly)

overly verbose ("US Dollars, Millions, Three-Month Trailing")

Critical for families

bar
time-series
distribution
correlation

Aspose property bindings

CategoryAxis.title
ValueAxis.title
AxisTitle.visibility