om2: OpenMetrics 2.0.0-rc1

docs/specs/om/open_metrics_spec_2_0.md

@@ -29,9 +29,9 @@ author:
       organization: Grafana Labs
 ---
 
-- Version: 2.0.0-rc0
+- Version: 2.0.0-rc1
 - Status: Experimental
-- Date: March 2026
+- Date: October 2026
 - Authors: Arthur Silva Sens, Bartłomiej Płotka, David Ashpole, György Krajcsovits, Owen Williams, Richard Hartmann
 - Emeritus: Ben Kochie, Brian Brazil, Rob Skillington
 
@@ -339,19 +339,19 @@ GaugeHistograms measure current distributions. Common examples are how long item
 
 A GaugeHistogram Sample MUST contain Gcount, Gsum values.
 
-The Gcount value MUST be equal to the number of measurements currently in the GaugeHistogram. The Gcount is a gauge semantically. The Gcount SHOULD be an integer. The Gcount SHOULD NOT be -Inf, +Inf, NAN, or negative.
+The Gcount value MUST be equal to the number of measurements currently in the GaugeHistogram. The Gcount is a gauge semantically. The Gcount SHOULD be an integer. The Gcount MUST NOT be negative. The Gcount SHOULD NOT be +Inf, NaN.
 
-Float and negative Gcount is allowed to make it possible to expose results of arithmetic operations on GaugeHistograms, such as the rate of change of a Histogram over time.
+Float Gcount is allowed to make it possible to expose results of arithmetic operations on GaugeHistograms, such as the rate of change of a Histogram over time.
 
 The Gsum value MUST be equal to the sum of all the measured values currently in the GaugeHistogram. The Gsum is a gauge semantically.
 
 A GaugeHistogram MUST measure values that are not NaN in either [Classic Buckets](#classic-buckets) or [Native Buckets](#native-buckets) or both. Measuring NaN is different for Classic and Native Buckets, see in their respective sections.
 
 If a GaugeHistogram stops measuring values in either Classic or Native Buckets and keeps measuring values in the other, it MUST clear and not expose the buckets it stopped measuring into. This avoids exposing different distribution from the two kind of buckets at the same time.
 
-Every Bucket MUST have well-defined boundaries and a value. Boundaries of a Bucket MUST NOT be NaN. Bucket values SHOULD be integers. Semantically, bucket values are gauges and SHOULD NOT be -Inf, +Inf, NaN, or negative.
+Every Bucket MUST have well-defined boundaries and a value. Boundaries of a Bucket MUST NOT be NaN. Bucket values are gauges semantically. Bucket values SHOULD be integers. Bucket values MUST NOT be negative. Bucket values SHOULD NOT be +Inf, NaN.
 
-Float and negative bucket values are allowed to make it possible to expose results of arithmetic operations on GaugeHistograms, such as the rate of change of a Histogram over time.
+Float bucket values are allowed to make it possible to expose results of arithmetic operations on GaugeHistograms, such as the rate of change of a Histogram over time.
 
 A GaugeHistogram SHOULD NOT include NaN measurements. If a GaugeHistogram includes NaN measurements, then NaN measurements MUST be counted in the Gcount and the Gsum MUST be NaN.
 
@@ -371,13 +371,13 @@ Summaries SHOULD NOT be used, because quantiles are not aggregatable and the use
 
 A Summary Sample MUST contain a Count, Sum and a set of quantiles.
 
-Semantically, Count and Sum values are counters so MUST NOT be NaN or negative. Count MUST be an integer.
+Semantically, Count is a counter so MUST NOT be NaN or negative. Count MUST be an integer. Sum MUST NOT be NaN. Sum is only a counter semantically as long as there are no negative event values measured by the Summary.
 
 A Summary SHOULD have a Start Timestamp.
 
 Start Timestamp MUST NOT be based on the collection period of quantile values.
 
-Quantiles are a map from a quantile to a value. An example is a quantile 0.95 with value 0.2 in a metric called `myapp_http_request_duration_seconds` which means that the 95th percentile latency is 200ms over an unknown timeframe. If there are no events in the relevant timeframe, the value for a quantile MUST be NaN. A Quantile's Metric's LabelSet MUST NOT have "quantile" label name. Quantiles MUST be between 0 and 1 inclusive. Quantile values MUST NOT be negative. Quantile values SHOULD represent the recent values. Commonly this would be over the last 5-10 minutes.
+Quantiles are a map from a quantile to a value. An example is a quantile 0.95 with value 0.2 in a metric called `myapp_http_request_duration_seconds` which means that the 95th percentile latency is 200ms over an unknown timeframe. If there are no events in the relevant timeframe, the value for a quantile MUST be NaN. A Quantile's Metric's LabelSet MUST NOT have "quantile" label name. Quantiles MUST be between 0 and 1 inclusive. Quantile values SHOULD represent the recent values. Commonly this would be over the last 5-10 minutes.
 
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