added STAM-translate extension

README.md

@@ -102,8 +102,7 @@ The following are currently defined:
 * [STAM-CSV](extensions/stam-csv) - Defines an alternative serialisation format using CSV.
 * [STAM Query Language (STAMQL)](extensions/stam-query) - This STAM extension defines a query language that allows end-users to formulate and subsequently execute searches on a STAM model. 
 * [STAM-Transpose](extensions/stam-transpose) - This is an extension on top of STAM that allows linking identical textual parts across resources, which we call transposition. This extension defines a vocabulary and prescribes functionality enabled through this vocabulary.
-
-Implementations *SHOULD* explicitly state which extensions they support.
+* [STAM-Translate](extensions/stam-translate) -  This is a more generic variant of transpositions, that allows relating any texts, even if not identical. It is useful for alignments of translations, corrections, normalisations, etc.. .This extension defines a vocabulary.
 
 ## Implementations
 

extensions/stam-translate/README.md

@@ -0,0 +1,41 @@
+# STAM-Translate: Linking related text selections
+
+## Introduction
+
+This is an extension on top of STAM that allows linking arbitrary textual parts
+(including across resources), which we call *translation*. This extension defines a
+vocabulary and prescribes functionality enabled through this vocabulary. This
+extension does not alter the underlying core data model.
+
+This is a simpler and more generic variant of the [STAM transpose](../stam-transpose/) extension.
+Whereas, transposition defines an exact mapping between any text selections, translations
+are texts that are somehow related but where the textual content is not identical.
+We use this term in a wide definition, so it covers not just natural language translation, but also things like
+transliteration, text normalisation, spelling correction, etc.. 
+
+The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
+"SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
+interpreted as described in RFC 2119.
+
+## Vocabulary
+
+A **translation** is, like everything in STAM, just an annotation. Annotations
+that describe translations are explicitly marked as being a translation by
+the following key in the annotation dataset with identifier
+``https://w3id.org/stam/extensions/stam-translate/``:
+
+* `Translation` (type: `Null`) - Marks an annotation as being a transposition. A transposition *MUST* use a `DirectionalSelector` or `CompositeSelector`, with underneath an `TextSelector` to target two or more text selections directly. 
+
+In case the translation is a natural language translation, this extension
+*RECOMMENDS* the use of the following key to identify the language:
+
+* `lang` (type: `String`) - The value *MUST* be an [iso-639-3 language code](https://iso639-3.sil.org/code_tables/639/data).
+
+## Functionality
+
+STAM implementations implementing this extension do not need to provide any specific functionality.
+
+## Limitations
+
+Translations do not hold the same properties as transpositions do, i.e. you can not use them to transpose annotations over.
+If you want to map equal text in different places, then use [transposigions (STAM-transpose extension)](../stam-transpose/README.md) instead.

extensions/stam-transpose/README.md

@@ -1,9 +1,9 @@
-# STAM-Transpose: Linking identical text selections across resources
+# STAM-Transpose: Linking identical text selections
 
 ## Introduction
 
 This is an extension on top of STAM that allows linking identical textual parts
-across resources, which we call *transposition*. This extension defines a
+(including across resources), which we call *transposition*. This extension defines a
 vocabulary and prescribes functionality enabled through this vocabulary. This
 extension does not alter the underlying core data model.
 
@@ -180,4 +180,5 @@ transposed variant:
 Transposition is by definition limited to relating text selections whilst
 preserving their textual content unmodified. It *MUST NOT* be used in cases
 where you want to relate text selections of a different nature, such as
-translations, transliterations, normalisations or corrections.
+translations, transliterations, normalisations or corrections. Use
+[translations (STAM-translate extension)](../stam-translate/README.md) for those.