Compare — prEN 18281

Differences are not changes. Every pair of the readings this record retained for a row is compared here, so a row read four times contributes six pairs before anything about the document has moved. A count of differences on these pages is a count of comparisons this record made between two readings it holds; this record publishes no count of changes to any document.

Source: prEN 18281 · CEN/CENELEC JTC 21 · Primary source (opens in new tab) cencenelec.eu
Dates: Retained readings first seen 2026-07-28; last seen 2026-11-02
Result: 1 pair: 0 render a difference, 0 withheld above the word ceiling, 1 refused by a rule, 0 differ in the digest and not in the words, 0 could not be measured

Result for one pair

Instrument: prEN 18281
Earlier: 2026-07-28 · reading first recorded 2026-07-28#7 · digest a18057838534383d…
Later: 2026-11-02 · reading first recorded 2026-10-09#1 · digest f2eb944050e96727…
Outcome: not comparable — No text from this document appears on this site, so no difference between two readings of it is shown either. The digests, the dates and the addresses are the record for this row. licence-restricted the row records its terms as restricted
Text retained: earlier yes · later yes
Reviewable: Nothing of the text is shown; the condition is named beside the outcome.

Link to this pair: https://gxplex.com/compare/pren-18281/?earlier=2026-07-28&later=2026-11-02

The pair shown is the first and the latest of the 98 days this record observed prEN 18281; any two of those days can be selected where scripting runs, and the link then names the two selected. A day with one digest names that digest’s reading by the day it was first recorded. Every pair of distinct retained readings is also in the Comparisons table below, each row at its own address.

This row holds 2 retained readings, which make 1 pair; of those, 0 render a difference below.

Each point below is one distinct digest of the normalised text this record retained for prEN 18281, addressed at the first observation that carried it. Two points can be compared where this record retains the text of both, where both are observations of the document itself, and where the terms of the source permit text from it to appear here.

Points

Distinct retained digests for prEN 18281, in the order this record first saw each
Point	First seen	Days seen	Digest	Answered at	Class	Words
2026-07-28 #7	2026-07-28	73 — last 2026-10-08	`a18057838534383d…`	https://www.cencenelec.eu/areas-of-work/cen-cenelec-topics/artificial-intelligence/	document	—
2026-10-09 #1	2026-10-09	25 — last 2026-11-02	`f2eb944050e96727…`	https://www.cencenelec.eu/areas-of-work/cen-cenelec-topics/artificial-intelligence/	document	—

The digest is of the NORMALISED text, not of the bytes served, so hashing the source as served will not reproduce it. Normalisation removes scripts, comments, navigation and page chrome, then strips tags. Where a tag is malformed the strip does not match it, so a fragment of a tag attribute can survive into the text that was hashed — a span shown here is a span of the normalised text this record hashed, and not necessarily of the document’s prose. The word column is a count of that normalised text and is left as — where the terms of the source mean this record does not read the text at all. The address is the one the request ANSWERED at, which is the record’s address; the address a request aimed at is testimony and is carried in the observation series.

Comparisons

1 pair can be formed from the 2 points above: 0 render a difference, 0 are withheld above the word ceiling, 1 are refused by a rule, 0 differ in the digest and not in the words, and 0 could not be measured.

1 of 1 refused on the terms of the source. This row records its terms as restricted. No text from the document appears on this site and none is compared here; the digests, the dates and the addresses above are what this record holds for it.

Every pair of the points above for prEN 18281, its result first, and what this record found for each
Earlier	Later	Outcome	Text retained	Reviewable	Verdict	What was found
2026-07-28#7 `a18057838534383d…`	2026-10-09#1 `f2eb944050e96727…`	not comparable licence-restricted	earlier yes · later yes	Nothing of the text is shown; the condition is named beside the outcome.	refused licence-restricted	No text from this document appears on this site, so no difference between two readings of it is shown either. The digests, the dates and the addresses are the record for this row. the row records its terms as restricted

What this row’s own record holds, and what its terms permit
Field	Value	What the value records
`text_retained`	`true`	Normalised text of at least one reading of this row is held here and is still on disk, so a digest can be re-checked against retained bytes. It is a fact about retention and not about publication: no snapshot is served.
`licence_class`	`restricted`	No text from this document appears on this site, so no difference between two readings of it is shown either. Every pair on this row is refused before any retained text is opened.

Rights envelope — how this record handles the text of each entry listed
Entry	`text_retained`	`licence_class`	`quote_allowed`	`snapshot_available`
prEN 18281	`true`	`restricted`	`false`	`true`

One row, for the entry whose readings this page compares.

Each value is read by the same function the API reads, and each field is defined in the published schema. None of the four is a grant.

The conditions, in the order they are evaluated

Conditions are evaluated in the order below and a pair names the FIRST one that fired. A pair refused early was never tested against the conditions beneath it, so a count against one condition is not a count of the pairs that would have failed it. Not measured is not zero: three of the conditions belong to the form of the comparison that takes two dates. The pair of days under “Result for one pair” above is that form, and those three are evaluated there. The pairs counted below are pairs of points, addressed as the store addresses them, and the three are never evaluated on those. Where this row holds no pair of points, no condition is evaluated on one, and every condition reads not measured.

The conditions, in evaluation order, and how many of this row’s 1 pair(s) of points each one refused
Condition	Pairs	What the condition states
`licence-restricted`	1	No text from this document appears on this site, so no difference between two readings of it is shown either. The digests, the dates and the addresses are the record for this row.
`licence-unread`	0	No reading of the terms this source states is recorded for the row. That is an absent reading rather than an absent term, and the row is handled here exactly as a restricted one until a reading is recorded.
`date-not-observed`	not measured	No observation of this row on that day holds retained text.
`date-not-unique`	not measured	That day holds more than one distinct retained digest for this row, so a date alone does not name one observation. The addressed form — the day and the sequence within it — does.
`one-point`	not measured	Both dates resolve to the same observation.
`referent-unclassified`	0	The class of one of these observations could not be read, so neither was shown to be an observation of the document itself.
`referent-class`	0	One of these observations is not of the document. A listing page that names the document and the document are different subjects, and a difference between them is not a difference in the document.
`referent-normalisation`	0	These two digests were taken over different kinds of text — one over markup, one over prose extracted from a file — so the words they yield differ for a reason that is not the publisher’s.
`referent-address`	0	These two observations answered at different addresses. A difference between them is at least in part a difference between two pages.
`text-not-retained`	0	No normalised text is held here for one of these observations, so there is nothing on this side to compare.
`snapshot-unreadable`	0	Normalised text is recorded for one of these observations and could not be read from this record.
`span-unverified`	0	A span this comparison would have shown could not be found, word for word and in that order, in the retained text it was drawn from. The comparison is withheld rather than shown: a phrase assembled out of words a publisher did not write next to each other is a fabricated measurement of what the publisher wrote.
`over-ceiling`	0	A faithful difference is longer than the word ceiling this site publishes under. Its words are withheld whole rather than cut to fit: a shortened quote is a fabricated measurement of what a publisher wrote. The figures below measure the difference and quote none of it.

A difference here is a difference between two readings this record retained. It is not a statement about what the document requires, what changed in substance, or whether anything follows from it. Where the words differ, the words are shown; where they differ by more than this site’s published ceiling, the counts are shown and the words are not. How this record is built.

Last updated: 2 November 2026