Robotics Systems Types

There are two issues with this:

1. Regardign the tagging scheme itself:
   • What is the canonical name and documentation for this tagging scheme?
   • The documentation under http://www.coli.uni-saarland.de/projects/sfb378/negra-corpus/ suggests that the tagging scheme is called Stuttgart-Tübingen-Tagset (STTS). Is this correct?
   • If so, what is the reason for choosing this particular scheme?
   • To which languages is this scheme applicable?
2. The individual enum items were not documented.

Based on the above issues, I made the following version of the enum and field:

        /**
         * Part-of-speech tags using a modified version of the
         * Stuttgart-Tübingen-Tagset (STTS).
         *
         * Differences w.r.t. STTS are:
         *
         * * ``KOMM`` instead of ``$,``
         * * ``END`` instead of ``$.``
         * * ``IPNCT`` instead of ``$(``
         *
         * @see http://www.coli.uni-saarland.de/projects/sfb378/negra-corpus/stts.asc
         *      "Description of the STTS (in German)" 
         */
        enum PosTag {

            /**
             * Attributives Adjektiv.
             */
            ADJA = 1;

            /**
             * Adverbiales oder prädikatives Adjektiv.
             */
            ADJD = 2;

            /**
             * Adverb.
             */
            ADV = 3;

            /**
             * Präposition; Zirkumposition links.
             */
            APPR = 4;

            /**
             * Präposition mit Artikel.
             */
            APPRART = 5;

            /**
             * Postposition.
             */
            APPO = 6;

            /**
             * Zirkumposition rechts.
             */
            APZR = 7;

            /**
             * Bestimmter oder unbestimmter Artikel.
             */
            ART = 8;

            /**
             * Kardinalzahl.
             */
            CARD = 9;

            /**
             * Fremdsprachliches Material.
             */
            FM = 10;

            /**
             * Interjektion.
             */
            ITJ = 11;

            /**
             * Ordinalzahl.
             */
            ORD = 12;

            /**
             * Unterordnende Konjunktion.
             */
            KOUI = 13;

            /**
             * Unterordnende Konjunktion.
             */
            KOUS = 14;

            /**
             * Nebenordnende Konjunktion.
             */
            KON = 15;

            /**
             * Vergleichskonjunktion.
             */
            KOKOM = 16;

            /**
             * Normales Nomen.
             */
            NN = 17;

            /**
             * Eigennamen.
             */
            NE = 18;

            /**
             * Substituierendes Demonstrativpronomen.
             */
            PDS = 19;

            /**
             * Attribuierendes Demonstrativpronomen.
             */
            PDAT = 20;

            /**
             * Substituierendes Indefinitpronomen.
             */
            PIS = 21;

            /**
             * Attribuierendes Indefinitpronomen ohne Determiner.
             */
            PIAT = 22;

            /**
             * Attribuierendes Indefinitpronomen mit Determiner.
             */
            PIDAT = 23;

            /**
             * Irreflexives Personalpronomen.
             */
            PPER = 24;

            /**
             * Substituierendes Possessivpronomen.
             */
            PPOSS = 25;

            /**
             * Attribuierendes Possessivpronomen.
             */
            PPOSAT = 26;

            /**
             * Substituierendes Relativpronomen.
             */
            PRELS = 27;

            /**
             * Attribuierendes Relativpronomen.
             */
            PRELAT = 28;

            /**
             * Reflexives Personalpronomen.
             */
            PRF = 29;

            /**
             * Substituierendes Interrogativpronomen.
             */
            PWS = 30;

            /**
             * Attribuierendes Interrogativpronomen.
             */
            PWAT = 31;

            /**
             * Adverbiales Interrogativ- oder Relativpronomen.
             */
            PWAV = 32;

            /**
             * Pronominaladverb.
             */
            PAV = 33;

            /**
             * "zu" vor Infinitiv.
             */
            PTKZU = 34;

            /**
             * Negationspartikel.
             */
            PTKNEG = 35;

            /**
             * Abgetrennter Verbzusatz.
             */
            PTKVZ = 36;

            /**
             * Antwortpartikel.
             */
            PTKANT = 37;

            /**
             * Partikel bei Adjektiv oder Adverb.
             */
            PTKA = 38;

            /**
             * SGML Markup.
             */
            SGML = 39;

            /**
             * Buchstabierfolge.
             */
            SPELL = 40;

            /**
             * Kompositions-Erstglied.
             */
            TRUNC = 41;

            /**
             * Finites Verb, voll.
             */
            VVFIN = 42;

            /**
             * Imperativ, voll.
             */
            VVIMP = 43;

            /**
             * Infinitiv, voll.
             */
            VVINF = 44;

            /**
             * Infinitiv mit "zu", voll.
             */
            VVIZU = 45;

            /**
             * Partizip Perfekt, voll.
             */
            VVPP = 46;

            /**
             * Finites Verb, aux.
             */
            VAFIN = 47;

            /**
             * Imperativ, aux.
             */
            VAIMP = 48;

            /**
             * Infinitiv, aux.
             */
            VAINF = 49;

            /**
             * Partizip Perfekt, aux.
             */
            VAPP = 50;

            /**
             * Finites Verb, modal.
             */
            VMFIN = 51;

            /**
             * Infinitiv, modal.
             */
            VMINF = 52;

            /**
             * Partizip Perfekt, modal.
             */
            VMPP = 53;

            /**
             * Nichtwort, Sonderzeichen enthaltend.
             */
            XY = 54;

            /**
             * Komma
             */
            KOMM = 55;

            /**
             * Satzbeendende Interpunktion.
             */
            END = 56;

            /**
             * Sonstige Satzzeichen; satzintern.
             */
            IPNCT = 57;

        }

        /**
         * Part-of-speech tag for this word.
         */
        optional PosTag part_of_speech_tag = 3;

Apart from the questions raised in 1., would this OK?

Applied in changeset rst-proto|ebd6d16853ff239e27fca161f7e46fd3a2bc6530.