It belongs to Housing, Infrastructure, and Basic Services, the part of the welfare catalog concerned with the habitability, affordability, and service infrastructure of the places where people live. The exact stored unit is PERCENT, the geographic presentation is global, the data publisher is United Nations Statistics Division, and the immutable numerical identity is UN-SDG-6.2.1#SHSANSAFE#Location=ALLAREA|Reporting Type=G#identity. The preliminary catalog candidate 16 is reconciled to the exact official series “Proportion of population using safely managed sanitation services, by urban/rural (%)” in PERCENT. This is a deliberate canonical correction: the database title names what the values actually measure, while the input wording remains in the reconciliation and audit trail. No hidden proxy label, fallback series, or silently substituted denominator remains. For catalog item 16, the provider definition is: Proportion of population using safely managed sanitation services, by urban/rural (%). The stored rows are the official World aggregate for SDG indicator 6.2.1, series SHSANSAFE, constrained to Location=ALLAREA|Reporting Type=G. That definition controls the denominator, population, reporting instrument, and statistical meaning. This Indicator records an observed outcome; it does not assert why that outcome changed. Welfare assessment for item 16 uses higherisbetter. Higher observations are treated as better welfare relative to the dated comparative reference. The direction applies to the stored official measure after the disclosed transformation, if any, rather than being inferred from an emotionally positive or negative title. No mathematical transformation is applied before persistence. Keeping title, series identity, unit, scope, transformation, and interpretation together prevents the record from mixing incompatible measurement concepts. The numerical observations for catalog item 16 were retrieved from United Nations Global SDG Indicators Database through https://unstats.un.org/SDGAPI/v1/sdg/Indicator/Data?indicator=6.2.1&areaCode=1&pageSize=1000 (opens in a new tab). The provider landing page is https://unstats.un.org/sdgs/dataportal/database?indicator=6.2.1 (opens in a new tab). The research package records the access date, exact dataset and series identifiers, dimension key Location=ALLAREA|Reporting Type=G, unit, provider metadata, transformation, and yearly aggregation label. The bounded Source and Evidence records can therefore reproduce which numbers were used without treating a generic homepage as row-level proof. Measurement provenance for item 16 follows this provider method: The United Nations database supplies a World aggregate for the exact series and dimension tuple. Factrail stores that published global observation and does not recompute it from country rows. 2018 uses the provider-published World aggregate; 2019 uses the provider-published World aggregate; 2020 uses the provider-published World aggregate; 2021 uses the provider-published World aggregate; 2022 uses the provider-published World aggregate; 2023 uses the provider-published World aggregate; 2024 uses the provider-published World aggregate. The output keeps full numerical precision through NormalLine, deviation, and interpretation calculations. Display clients may round for readability, but the persisted value is not squeezed into a zero-to-one score and is not rounded before calculation. The item 16 NormalLine starts on 2018-01-01 at 57.416137695 PERCENT. 75th percentile of retained official World observations across the disclosed publication window. The calculation keeps the source unit, dimensions, and transformation fixed and is a comparative reference rather than an invented statutory target. For zeroisnorm, the value is exactly zero and is never relaxed because non-zero observations are common. For every item 16 point, normallinevalue copies that dated line and deviationfromnormal is stored in raw-unit terms as observation minus NormalLine. Arithmetic sign and welfare sign are separate. A positive raw deviation is adverse for lowerisbetter, favourable for higherisbetter, and adverse above zero for zeroisnorm. The custom governance score retains its provider scale and uses the public methodology explanation rather than title sentiment. The complete retained sequence is 2018: 52.78203583 PERCENT; 2019: 54.24112701 PERCENT; 2020: 55.18129349 PERCENT; 2021: 56.10706711 PERCENT; 2022: 57.03186798 PERCENT; 2023: 57.80040741 PERCENT; 2024: 58.49518967 PERCENT. The first observation is 52.78203583 PERCENT in 2018 and the latest is 58.49518967 PERCENT in 2024. The absolute change is 5.71315384 PERCENT, equivalent to 10.824049793% of the absolute starting level. The minimum observed value is 52.78203583 PERCENT, and the maximum is 58.49518967 PERCENT. For catalog item 16, the latest observation differs from the NormalLine by 1.079051975 PERCENT and is classified as positive under higherisbetter. That classification is a deterministic comparison, not a causal explanation or editorial verdict. A movement may reflect real change, altered reporting coverage, revised estimates, a changed survey frame, or several of those at once. There are 7 retained item 16 observations in the selected 2018-2025 research window. The retained observations satisfy the minimum temporal rule without interpolation, extrapolation, or forward filling. Missing years are absent observations, not zeroes. The sequence is intentionally irregular when the official source is irregular, because a smooth-looking line created by invented values would be methodologically false. The displayed global item 16 sequence has one consistent numerical identity: UN-SDG-6.2.1#SHSANSAFE#Location=ALLAREA|Reporting Type=G#identity. No second source series is spliced into a gap, no latest value is copied into a missing year, and no country-only observation is relabelled as a World value. If the source later adds or revises an observation, the update must arrive as a new reviewed research package with its own checksum and audit record. A defensible graph edge requires an existing Driver, direction, strength, lag, confidence, and Source/Evidence that supports the mechanism. The outcome series alone cannot establish that causal chain. For item 16, importance weight 0.8 is generated by indicator-importance-rubric-v1. Its five committed components are directness 0.75, population reach 0.75, persistence 0.8, effect on human capabilities 0.85, and overlap control 0.75. The formula weights them 0.35, 0.25, 0.20, 0.15, and 0.05, then rounds to the nearest 0.05. The value is deterministic and reproducible; it is not an intuitive score assigned while drafting prose. The 2018-2024 sequence for item 16 is too short for strong causal or structural claims. Cross-economy comparability can be affected by institutional definitions, survey coverage, modelled estimates, missing observations, classification practices, revisions, and unequal statistical capacity. A global aggregate or unweighted reporting-economy mean can also conceal distributional extremes and should not be used as an individual-level estimate. The item 16 NormalLine is a transparent comparative reference, not a claim that every jurisdiction has the same legal target or feasible frontier. The source may revise both historical points and metadata. Any later refresh must preserve the earlier Source, Evidence, checksum, and audit trail; it must not mutate the meaning of an already reviewed series identity.