Toronto_SSIM preserved-data provenance, SSIMmap 0.4.1

279 Aggregate Dissemination Areas (ADAs), Toronto, 2021 Census geography.
Columns: ADAUID, PP, Commute, CIMD, geometry.
All values and geometry are unchanged from SSIMmap 0.4.0. Earlier package documentation describing 2016 Census Tracts and a household commuting share was incorrect.

Verified preserved calculation
DA numerator: 2021 Census characteristic 2601, "Commute to a different census subdivision (CSD) and census division (CD) within province or territory of residence".
DA denominator: 2021 Census characteristic 1, total population, not household count or workers.
For positive-population DAs: 100 * numerator / total population, rounded half-up to two decimal places. All 3,743 stored DA percentages are non-missing. The nine zero-population DAs have stored Pct_commute=0 and are included in the ADA means. This describes the preserved values; the original zero-denominator handling code was not recovered.
ADA Commute: unweighted mean of all stored DA percentages for all DAs returned by spatial intersection, including DAs whose boundaries only touch the ADA. This is not a pooled ADA numerator/denominator ratio, not population-weighted, and not a household or worker percentage. The numerator category excludes other outside-CSD destinations, including interprovincial commuting; it must not be relabeled as all outside-CSD commuting.

Official-source audit
All 3,743 DA total-population entries match Census characteristic 1.
All 3,727 publicly disclosed numerator entries match characteristic 2601.
The remaining 16 official numerator cells are suppressed (FLAG 6), but the preserved source stores zero: 9 have zero total population and 7 have positive total population. The suppressed values cannot be independently verified from the public release, and the original code responsible for their zero representation was not recovered. Do not describe this as a verified suppression-to-zero processing rule.
The 16 suppressed source DAs enter 45 ADA means through spatial intersection (including boundary touches): 24 ADAs intersect a zero-population suppressed DA and 22 intersect a positive-population suppressed DA, with one ADA in both groups.
Twenty-four source DAs have positive characteristic 2602 (commuting to a different province or territory), confirming that characteristic 2601 is narrower than all outside-CSD commuting.

Author decision
Preserve the existing numeric analysis and record its calculation and discrepancies rather than replace the data or reaggregate it in this revision. The metadata correction does not change the supplied numeric example or establish a population-weighted ADA commuting rate.

Official sources
Census characteristic codelist:
https://api.statcan.gc.ca/census-recensement/profile/sdmx/rest/codelist/STC_CP/CL_CHARACTERISTIC/latest
Example DA query including population and commuting categories:
https://api.statcan.gc.ca/census-recensement/profile/sdmx/rest/data/STC_CP,DF_DA/A5.2021S051235200958.1.1+57+2598+2599+2600+2601+2602.1/key?format=csv

CIMD source label
The supplied source CSV labels the CIMD score as "Residential instability Scores"; the PP source field is SCORESOC. The full provenance of the final ADA-level CIMD aggregation and the precise national/provincial CIMD source edition have not been reconstructed. The existing numeric example is preserved, and the dimension label is corrected to residential instability.
