There are two items in this CR, for context see https://discourse.openehr.org/t/iso-8601-correctness-in-openehr-specs/2579/4 ITEM 1: In the Foundation Types spec, I found that it mentions many times that “partial dates/times” are supported by ISO 8601, though the word “partial” is not even mentioned in the ISO standard. The term they use is “reduced precision” instead of “partial”. I think we need to stick to their terminology if we state that something is supported by their standard. Thomas and Ian mentioned "partial", "partial date", "partial time", etc. are terms commonly used and understood in health informatics. The issue is not with the term itself, but using the term "partial" when referencing the ISO 8601 standard and they don't use it could be confusing for people reading both specs. e have phrases like: “… These are concrete types based on the ISO 8601 (2019) date/time standard semantics, which supports partial dates, times…” “…the ISO 8601 ‘partial’ and ‘extended’ semantics…” “Partial variants of Iso8601_date_time can include missing hours, days and months, whereas ISO 8601:2019 (section 4.3.3 c) only allows missing seconds and minutes…” “Abstract ancestor type of ISO 8601 types, defining interface for ‘extended’ and ‘partial’ concepts from ISO 8601.” https://specifications.openehr.org/releases/BASE/Release-1.2.0/foundation_types.html#_time_types Then you search the whole ISO standard and there is no mention of “partial”, when we say it is supported by the standard, there is something confusing here. ISO uses “reduced precision”, term which appears 19 times in their spec against zero times for “partial”. I’m not saying we need to change our specs, but add a clarification that when we say “partial date” in the context of what ISO8601 supports, in the ISO standard that is “reduced precision”. Thomas mentioned "I would suggest we say things like ‘partial dates are implemented using ISO 8601 reduced precision date strings’", which is a reasonable clarification. NOTE: instead of "string" I would also suggest to use "expression" or "representation" which are terms used in the ISO 8601 spec. For instance, in the ISO spec, these terms are used to name these values (examples below): Expression: 1981-10-24 Representation: YYYY-MM-DD ITEM 2: In the foundation types spec we use “compact form” and “extended form” referring to ISO defined representations or expressions, while the term “compact” doesn’t appear in the ISO spec. The correct terms are “basic format” and “extended format” (note “format” instead of “form”). For “compact form”, we are actually referring something directly defined in the ISO standard, and their spec doesn’t use that term at all. So in this case I would suggest to change all “compact” and “form” to “basic” and “format”. NOTE: in the ISO spec there is this clarification "Representations (also referred to as “format representations”) give rise to expressions for dates, times, intervals and recurring intervals.". So they use "representation" and "format" interchangeably. ISO 8601-1_2019 section 3.2.1