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doc/internationalization.md

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+gRPC Internationalization
+=========================
+
+As a universal RPC framework, gRPC needs to be fully usable within/across different international environments. 
+This document describes gRPC API and behavior specifics when used in a non-english environment.
+
+## API Concepts
+
+While some API elements need to be able to represent non-english content, some are intentionally left as ASCII-only
+for simplicity & performance reasons.
+
+### Method name (in RPC Invocation)
+Method names are ASCII-only. Most gRPC services will use protobuf which only allows ASCII based method names anyway.
+Also, handling method names is a very hot code path.
+
+Recommended representation in language-specific APIs: string type.
+
+### Host name (in RPC Invocation)
+Host names are punycode encoded. Currently, the punycode needs to be provided by the user.
+
+Recommended representation in language-specific APIs: string/unicode string.
+
+NOTE: overriding host name when invoking RPCs is only supported by C-core based gRPC implementations.
+
+### Status detail/message (accompanies RPC status code)
+
+Status messages are expected to contain national-alphabet characters.
+Allowed values are unicode strings (content will be percent-encoded on the wire).
+
+Recommended representation in language-specific APIs: unicode string.
+
+### Metadata key
+Allowed values are defined by HTTP/2 standard (metadata keys are represented as HTTP/2 header/trailer names).
+
+Recommended representation in language-specific APIs: string.
+
+### Metadata value (text-valued metadata)
+Allowed values are defined by HTTP/2 standard (metadata values are represented as HTTP/2 header/trailer text values).
+
+Recommended representation in language-specific APIs: string.
+
+### Channel name
+
+TBD