Move attribute documents to semantic-conventions repository

specification/common/README.md

@@ -53,9 +53,9 @@ indices that are kept in sync (e.g., two attributes `header_keys` and `header_va
 both containing an array of strings to represent a mapping
 `header_keys[i] -> header_values[i]`).
 
-See [Attribute Naming](attribute-naming.md) for naming guidelines.
+See [Attribute Naming](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/general/attribute-naming.md) for naming guidelines.
 
-See [Requirement Level](attribute-requirement-level.md) for requirement levels guidelines.
+See [Requirement Level](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/general/attribute-requirement-level.md) for requirement levels guidelines.
 
 See [this document](attribute-type-mapping.md) to find out how to map values obtained
 outside OpenTelemetry into OpenTelemetry attribute values.

specification/common/attribute-naming.md

@@ -1,156 +1,4 @@
 # Attribute Naming
 
-**Status**: [Stable](../document-status.md)
-
-<details>
-<summary>Table of Contents</summary>
-
-<!-- toc -->
-
-- [Name Pluralization guidelines](#name-pluralization-guidelines)
-- [Name Reuse Prohibition](#name-reuse-prohibition)
-- [Recommendations for OpenTelemetry Authors](#recommendations-for-opentelemetry-authors)
-- [Recommendations for Application Developers](#recommendations-for-application-developers)
-- [otel.* Namespace](#otel-namespace)
-
-<!-- tocstop -->
-
-</details>
-
-_This section applies to Resource, Span, Log, and Metric attribute names (also
-known as the "attribute keys"). For brevity within this section when we use the
-term "name" without an adjective it is implied to mean "attribute name"._
-
-Every name MUST be a valid Unicode sequence.
-
-_Note: we merely require that the names are represented as Unicode sequences.
-This specification does not define how exactly the Unicode sequences are
-encoded. The encoding can vary from one programming language to another and from
-one wire format to another. Use the idiomatic way to represent Unicode in the
-particular programming language or wire format._
-
-Names SHOULD follow these rules:
-
-- Use namespacing to avoid name clashes. Delimit the namespaces using a dot
-  character. For example `service.version` denotes the service version where
-  `service` is the namespace and `version` is an attribute in that namespace.
-
-- Namespaces can be nested. For example `telemetry.sdk` is a namespace inside
-  top-level `telemetry` namespace and `telemetry.sdk.name` is an attribute
-  inside `telemetry.sdk` namespace.
-  Note: the fact that an entity is located within another entity is typically
-  not a sufficient reason for forming nested namespaces. The purpose of a
-  namespace is to avoid name clashes, not to indicate entity hierarchies. This
-  purpose should primarily drive the decision about forming nested namespaces.
-
-- For each multi-word dot-delimited component of the attribute name separate the
-  words by underscores (i.e. use snake_case). For example `http.response.status_code`
-  denotes the status code in the http namespace.
-
-- Names SHOULD NOT coincide with namespaces. For example if
-  `service.instance.id` is an attribute name then it is no longer valid to have
-  an attribute named `service.instance` because `service.instance` is already a
-  namespace. Because of this rule be careful when choosing names: every existing
-  name prohibits existence of an equally named namespace in the future, and vice
-  versa: any existing namespace prohibits existence of an equally named
-  attribute key in the future.
-
-## Name Pluralization guidelines
-
-- When an attribute represents a single entity, the attribute name SHOULD be singular.
-  Examples: `host.name`, `db.user`, `container.id`.
-
-- When attribute can represent multiple entities, the attribute name SHOULD be pluralized
-  and the value type SHOULD be an array. E.g. `process.command_args` might include multiple
-  values: the executable name and command arguments.
-
-- When an attribute represents a measurement,
-  [Metric Name Pluralization Guidelines](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/general/metrics.md#pluralization)
-  SHOULD be followed for the attribute name.
-
-## Name Reuse Prohibition
-
-A new attribute MUST NOT be added with the same name as an attribute that
-existed in the past but was renamed (with a corresponding schema file).
-
-When introducing a new attribute name check all existing schema files to make
-sure the name does not appear as a key of any "rename_attributes" section (keys
-denote old attribute names in rename operations).
-
-## Recommendations for OpenTelemetry Authors
-
-- All names that are part of OpenTelemetry semantic conventions SHOULD be part
-  of a namespace.
-
-- When coming up with a new semantic convention make sure to check existing
-  namespaces ([Semantic Conventions](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/README.md))
-  to see if the new name fits.
-
-- When a new namespace is necessary consider whether it should be a top-level
-  namespace (e.g. `service`) or a nested namespace (e.g. `service.instance`).
-
-- Semantic conventions exist for four areas: for Resource, Span, Log, and Metric
-  attribute names. In addition, for spans we have two more areas: Event and Link
-  attribute names. Identical namespaces or names in all these areas MUST have
-  identical meanings. For example the `http.request.method` span attribute name denotes
-  exactly the same concept as the `http.request.method` metric attribute, has the same
-  data type and the same set of possible values (in both cases it records the
-  value of the HTTP protocol's request method as a string).
-
-- Semantic conventions MUST limit names to printable Basic Latin characters
-  (more precisely to
-  [U+0021 .. U+007E](https://en.wikipedia.org/wiki/Basic_Latin_(Unicode_block)#Table_of_characters)
-  subset of Unicode code points). It is recommended to further limit names to
-  the following Unicode code points: Latin alphabet, Numeric, Underscore, Dot
-  (as namespace delimiter).
-
-## Recommendations for Application Developers
-
-As an application developer when you need to record an attribute first consult
-existing [semantic conventions](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/README.md).
-If an appropriate name does not exists you will need to come up with a new name.
-To do that consider a few options:
-
-- The name is specific to your company and may be possibly used outside the
-  company as well. To avoid clashes with names introduced by other companies (in
-  a distributed system that uses applications from multiple vendors) it is
-  recommended to prefix the new name by your company's reverse domain name, e.g.
-  `com.acme.shopname`.
-
-- The name is specific to your application that will be used internally only. If
-  you already have an internal company process that helps you to ensure no name
-  clashes happen then feel free to follow it. Otherwise it is recommended to
-  prefix the attribute name by your application name, provided that
-  the application name is reasonably unique within your organization (e.g.
-  `myuniquemapapp.longitude` is likely fine). Make sure the application name
-  does not clash with an existing semantic convention namespace.
-
-- It is not recommended to use existing OpenTelemetry semantic convention namespace
-  as a prefix for a new company- or application-specific attribute name. Doing so
-  may result in a name clash in the future, if OpenTelemetry decides to use that
-  same name for a different purpose or if some other third party instrumentation
-  decides to use that exact same attribute name and you combine that instrumentation
-  with your own.
-
-- The name may be generally applicable to applications in the industry. In that
-  case consider submitting a proposal to this specification to add a new name to
-  the semantic conventions, and if necessary also to add a new namespace.
-
-It is recommended to limit names to printable Basic Latin characters
-(more precisely to
-[U+0021 .. U+007E](https://en.wikipedia.org/wiki/Basic_Latin_(Unicode_block)#Table_of_characters)
-subset of Unicode code points).
-
-## otel.* Namespace
-
-Attribute names that start with `otel.` are reserved to be defined by
-OpenTelemetry specification. These are typically used to express OpenTelemetry
-concepts in formats that don't have a corresponding concept.
-
-For example, the `otel.scope.name` attribute is used to record the
-instrumentation scope name, which is an OpenTelemetry concept that is natively
-represented in OTLP, but does not have an equivalent in other telemetry formats
-and protocols.
-
-Any additions to the `otel.*` namespace MUST be approved as part of
-OpenTelemetry specification.
+This page has moved to
+[github.com/open-telemetry/semantic-conventions/docs/general/attribute-naming.md](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/general/attribute-naming.md).

specification/common/attribute-requirement-level.md

@@ -1,76 +1,4 @@
 # Attribute Requirement Levels for Semantic Conventions
 
-**Status**: [Stable](../document-status.md)
-
-<details>
-<summary>Table of Contents</summary>
-
-<!-- toc -->
-
-- [Required](#required)
-- [Conditionally Required](#conditionally-required)
-- [Recommended](#recommended)
-- [Opt-In](#opt-in)
-- [Performance suggestions](#performance-suggestions)
-
-<!-- tocstop -->
-
-</details>
-
-_This section applies to Log, Metric, Resource, and Span, and describes requirement levels for attributes defined in semantic conventions._
-
-Attribute requirement levels apply to the [instrumentation library](../glossary.md#instrumentation-library).
-
-The following attribute requirement levels are specified:
-
-- [Required](#required)
-- [Conditionally Required](#conditionally-required)
-- [Recommended](#recommended)
-- [Opt-In](#opt-in)
-
-The requirement level for an attribute is specified by semantic conventions depending on attribute availability across instrumented entities, performance, security, and other factors. When specifying requirement levels, a semantic convention MUST take into account signal-specific requirements.
-
-For example, Metric attributes that may have high cardinality can only be defined with `Opt-In` level.
-
-A semantic convention that refers to an attribute from another semantic convention MAY modify the requirement level within its own scope. Otherwise, requirement level from the referred semantic convention applies.
-
-<!-- TODO(jsuereth) - make examples not break on changes to semconv -->
-For example, [Database semantic convention](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/database/README.md) references `network.transport` attribute defined in [General attributes](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/general/README.md) with `Conditionally Required` level on it.
-
-## Required
-
-All instrumentations MUST populate the attribute. A semantic convention defining a Required attribute expects an absolute majority of instrumentation libraries and applications are able to efficiently retrieve and populate it, and can additionally meet requirements for cardinality, security, and any others specific to the signal defined by the convention. `http.request.method` is an example of a Required attribute.
-
-_Note: Consumers of telemetry can detect if a telemetry item follows a specific semantic convention by checking for the presence of a `Required` attribute defined by such convention. For example, the presence of the `db.system` attribute on a span can be used as an indication that the span follows database semantics._
-
-## Conditionally Required
-
-All instrumentations MUST populate the attribute when the given condition is satisfied. The semantic convention of a `Conditionally Required` attribute MUST clarify the condition under which the attribute is to be populated.
-
-`http.route` is an example of a conditionally required attribute that is populated when the instrumented HTTP framework provides route information for the instrumented request. Some low-level HTTP server implementations do not support routing and corresponding instrumentations can't populate the attribute.
-
-When a `Conditionally Required` attribute's condition is not satisfied, and there is no requirement to populate the attribute, semantic conventions MAY provide special instructions on how to handle it. If no instructions are given and if instrumentation can populate the attribute, instrumentation SHOULD use the `Opt-In` requirement level on the attribute.
-
-<!-- TODO(jsuereth) - make examples not break on changes to semconv -->
-For example, `server.address` is `Conditionally Required` by the [Database convention](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/database/README.md) when available. When `network.peer.address` is available instead, instrumentation can do a DNS lookup, cache and populate `server.address`, but only if the user explicitly enables the instrumentation to do so, considering the performance issues that DNS lookups introduce.
-
-## Recommended
-
-Instrumentations SHOULD add the attribute by default if it's readily available and can be [efficiently populated](#performance-suggestions). Instrumentations MAY offer a configuration option to disable Recommended attributes.
-
-Instrumentations that decide not to populate `Recommended` attributes due to [performance](#performance-suggestions), security, privacy, or other consideration by default, SHOULD allow for users to
-opt-in to emit them as defined for the `Opt-In` requirement level (if the attributes are logically applicable).
-
-## Opt-In
-
-Instrumentations SHOULD populate the attribute if and only if the user configures the instrumentation to do so. Instrumentation that doesn't support configuration MUST NOT populate `Opt-In` attributes.
-
-This attribute requirement level is recommended for attributes that are particularly expensive to retrieve or might pose a security or privacy risk. These should therefore only be enabled explicitly by a user making an informed decision.
-
-## Performance suggestions
-
-Here are several examples of expensive operations to be avoided by default:
-
-- DNS lookups to populate `server.address` when only an IP address is available to the instrumentation. Caching lookup results does not solve the issue for all possible cases and should be avoided by default too.
-- forcing an `http.route` calculation before the HTTP framework calculates it
-- reading response stream to find `http.response.body.size` when `Content-Length` header is not available
+This page has moved to
+[github.com/open-telemetry/semantic-conventions/docs/general/attribute-requirement-level.md](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/general/attribute-requirement-level.md).