anchor.diff:  The creator on the referral module is the author of the referral. The actual writer (mmlCi:CreatorInfo) is possible to differ from the person referred (mmlRe:referFrom).
   
   ===== extRefs
  -
  -紹介状モジュール内の mmlCm:extRef エレメントを記載する．記載されている外部リンク情報の数だけ繰り返す．
  +This element contains mmlCm:extRef in this mmlRe:ReferralModule, is repeatable as the number of outer links.
   
   ===== content
  -
  -一つの content に一つだけ紹介状モジュールを入れる．
  -
  -.エレメント一覧表
  +Each content has one referral module.
  +
  +.List of the elements.
   [options="header"]
   |===
   | |Elements|Attribute|Data types|Occurrence|TableId
  
positive.code:     <mmlPs:medication>
        <mmlPs:batchNo>1</mmlPs:batchNo>
        <mmlPs:medicine>
          <mmlPs:name>プレドニゾロン錠 5mg</mmlPs:name>
          <mmlPs:code mmlPs:system="YJ">61222033</mmlPs:code>
        </mmlPs:medicine>
        <mmlPs:dose>4</mmlPs:dose>
        <mmlPs:doseUnit>錠</mmlPs:doseUnit>
        <mmlPs:frequencyPerDay>1</mmlPs:frequencyPerDay>
        <mmlPs:startDate>2015-05-13</mmlPs:startDate>
        <mmlPs:duration>P14D</mmlPs:duration>
        <mmlPs:instruction>内服 1回 朝食前</mmlPs:instruction>
      </mmlPs:medication>
    </mmlPs:PrescriptionModule>
  </mmlRe:medication>
  
  ===== M21.13.2. mmlInj:InjectionModule
  【内容】構造はコンテンツモジュールmmlInj:InjectionModule参照 +
  【省略】省略可 +
  
  ===== M21.13.3. mmlCm:extRef
  【内容】外部参照図，ファイル，表などを添付するときに，MML 共通形式 (外部参照形式) を用いる． +
  【繰り返し設定】繰り返しあり．外部参照ファイルが複数あれば，数だけ繰り返す．
  
  ===== M21.14. mmlRe:referPurpose
  【内容】紹介目的 +
  【データ型】string +
  【省略】不可 +
  【文書のレイアウト】XHTML 使用可
  
  ===== M21.15. mmlRe:remarks
  【内容】備考．テキストと mmlCm:extRef の混在可 +
  【データ型】string +
  【省略】省略可 +
  【文書のレイアウト】XHTML 使用可
  
  ===== M21.15.1. mmlCm:extRef
  【内容】外部参照図，ファイル，表などを添付するときに，MML 共通形式 (外部参照形式) を用いる． +
  【繰り返し設定】繰り返しあり．外部参照ファイルが複数あれば，数だけ繰り返す． +
  
  ===== M21.16. mmlRe:referToFacility
  【内容】紹介先医療機関名．施設情報を入れる親エレメント +
  【省略】不可
  
  ===== M21.16.1. mmlFc:Facility
  【内容】紹介先医療機関．構造はMML共通形式(施設情報形式)mmlFc:Facilityを利用する． +
  【省略】不可
  
  ===== M21.16.2. mmlDp:Department
  【内容】紹介先診療科．構造は MML 共通形式 (施設情報形式)mmlDp:Departmentを利用する． +
  
negative.code: |M21.17.1.|mmlPsi:PersonalizedInfo| | | |
  |M21.18.|mmlRe:referToUnknownName| |string|?|
  |===
  Occurrences; blank: 1, ?: 0 or 1, +: more than 1, *: more than 0 +
    #REQUIRED: mandatory attribute, #IMPLIED: optional attribute
  
  ==== Elements in details
  ===== M21. mmlRe:ReferralModule
  [horizontal]
  Description:: Referral module. Each instance of this module contains single referral letter by the doctor.
  Occurrence:: 1..1.
  
  ===== M21.1. mmlPi:PatientModule
  [horizontal]
  Description:: Patient information module, which contains name, address, telecoms, etc. Further information is available in mmlPi:PatientModule description.
  Occurrence:: 1..1.
  
  ===== M21.2. mmlRe:occupation
  [horizontal]
  Description:: Occupation.
  Occurrence:: 0..1.
  Data type:: string.
  Layout:: XHTML available.
  
  ===== M21.3. mmlRe:referFrom
  [horizontal]
  Description:: Parent element to include the information of referrer.
  Occurrence:: 1..1.
  
  ===== M21.3.1. mmlPsi:PersonalizedInfo
  [horizontal]
  Descrption:: The person who refer patient to, the schema was mmlPsi:PersonalizedInfo.
  Occurence:: 1..1.
  
  ===== M21.4. mmlRe:title
  [horizontal]
  Description:: title of this instance, such as "Referral", or others.
  Data type:: string.
  Occurence:: 1..1.
  
  ==== M21.5. mmlRe:greeting
  [horizontal]
  Description:: the greeting of this referral letter.
  Data type:: string.
  Occurrence::  0..1.
  Layout:: XHTML available.
  
  .Example
  [source, xml]
  <mmlRe:greeting>
  To whom it may concern,<xhtml:br/>
  Mr Yoshihara is a xx years old male, who had injured his left leg.
  ...
  Yours sincerely,
  Shinji Kobayashi
  </mmlRe:greeting>
  
  ===== M21.6. mmlRe:chiefComplaints
  [horizontal]
  Description:: Chief complaints.
  Deta types:: string.
  Occurrence:: 1..1.
  Layout:: XHTML available.
  
  ===== M21.7. mmlRe:clinicalDiagnosis
  [horizontal]
  Description:: This element include unstructured diagnosis layouted by XHTML. If the diagnosis should be structured, mmlRd:RegisteredDiganosis module is available and the instance should be bundled by the same groupId.
  Data type:: string.
  Occurrence:: 0..1.
  Layout:: XHTML available.
  
  ===== M21.8. mmlRe:pastHistory
  [horizontal]
  Description:: past history. mixed expression is allowable with mmlCm:extRef and text.
  Data type:: string.
  Occurrence:: 0..1.
  Layout:: XHTML available.
  
  ===== M21.8.1. mmlCm:extRef
  [horizontal]
  Description:: external reference for the figures, such as graph. The structure is mmlCm:extRef.
  Occurrence:: 0..*, repeatable as the nubmer of external reference files.
  
  ===== M21.9. mmlRe:familyHistory
  [horizontal]
  Description:: Family history, mixed expression is allowable with mmlCm:extRef and text.
  Data type:: string.
  Occurrence:: 0..1.
  Layout:: XHTML available.
  
  ===== M21.9.1. mmlCm:extRef
  [horizontal]
  Description:: external referential figures, or tables. mmlCm:extRef structure is available.
  Occurrence:: 0..*, repeatable as the number of external files to refer.
  
  ===== M21.10. mmlRe:presentIllness
  [horizontal]
  Description:: Present illness, mixed expression is allowable with mmlCm:extRef and text.
  Data type:: string.
  Occurrence: 1..1.
  Layout:: XHTML available.
  
  ===== M21.10.1. mmlCm:extRef
  [horizontal]
  Description:: figures for external references. mmlCm:extRef format is available.
  Occurence:: 0..*, repeatble as the number of files.
  
  ===== M21.11. mmlRe:testResults
  [horizontal]
  Description:: the results of the tests, mixed expression is allowable with mmlCm:extRef and text.
  Data type:: string.
  Occurrence:: 0..1.
  Layout:: XHTML available.
  
  ===== M21.11.1. mmlCm:extRef
  [horizontal]
  Description:: external referential figures, or tables. mmlCm:extRef structure is available.
  Occurrence:: 0..*, repeatable as the number of external files to refer.
  
  ===== M21.12. mmlSm:clinicalCourse
  [horizontal]
  Description:: Clinical course. The structure should refer to mmlSm:clinicalCourse(Clinical Summary module).
  Data type:: string.
  Occurrence:: 0..1.
  
  ===== M21.13. mmlRe:medication
  [horizontal]
  Description:: Active prescription. mixed expression is allowable with mmlCm:extRef and text.
  Data type:: string.
  Occurrence:: 0..1.
  Layout:: XHTML available.
  
  ===== M21.13.1. mmlPs:PrescriptionModule
  [horizontal]
  Description:: The scheme should be referred to mmlPs:PrescriptionModule.
  Occurrence:: 0..1.
  
  .Example
  [source, xml]
  <mmlRe:medication>
    Prescription on discharge
  