Here's an example found on the web at: http://www.winterdom.com/dev/bts/BTSFFSchemaTut2.html
(and you might want to read it there since this will probably line-wrap badly)

They seem to have b:recordInfo for sequences and b:fieldInfo for elements of simple type.

They use very long verbose property names like preserve_delimiter_for_empty_data="true" for example.

<?xml version="1.0" encoding="utf-16"?>
<xs:schema xmlns="urn:schemas-winterdom-com:multifile" xmlns:b="http://schemas.microsoft.com/BizTalk/2003" 
elementFormDefault="qualified" targetNamespace="urn:schemas-winterdom-com:multifile" xmlns:xs="http://www.w3.org/2001/
XMLSchema">
  <xs:annotation>
    <xs:appinfo>
      <b:schemaInfo count_positions_by_byte="false" standard="Flat File" root_reference="MultiFile" case="upper" />
      <schemaEditorExtension:schemaInfo namespaceAlias="b" extensionClass="Microsoft.BizTalk.FlatFileExtension.
FlatFileExtension" standardName="Flat File" xmlns:schemaEditorExtension="http://schemas.microsoft.com/BizTalk/2003/
SchemaEditorExtensions" />
    </xs:appinfo>
  </xs:annotation>
  <xs:element name="MultiFile">
    <xs:annotation>
      <xs:appinfo>
        <b:recordInfo structure="delimited" preserve_delimiter_for_empty_data="true" suppress_trailing_delimiters="false
" sequence_number="1" child_order="infix" child_delimiter_type="hex" child_delimiter="0x2E 0x0D 0x0A" />
      </xs:appinfo>
    </xs:annotation>
    <xs:complexType>
      <xs:sequence>
        <xs:annotation>
          <xs:appinfo>
            <b:groupInfo sequence_number="0" />
          </xs:appinfo>
        </xs:annotation>
        <xs:element name="CityList">
          <xs:annotation>
            <xs:appinfo>
              <b:recordInfo sequence_number="1" structure="delimited" preserve_delimiter_for_empty_data="false" 
suppress_trailing_delimiters="true" tag_name="CITYLIST
" child_order="postfix" child_delimiter_type="hex" 
child_delimiter="0x0D 0x0A" />
            </xs:appinfo>
          </xs:annotation>
          <xs:complexType>
            <xs:choice minOccurs="0" maxOccurs="unbounded">
              <xs:annotation>
                <xs:appinfo>
                  <b:groupInfo sequence_number="0" />
                </xs:appinfo>
              </xs:annotation>
              <xs:element name="City">
                <xs:annotation>
                  <xs:appinfo>
                    <b:recordInfo sequence_number="1" structure="positional" preserve_delimiter_for_empty_data="true" 
suppress_trailing_delimiters="false" tag_name="C" />
                  </xs:appinfo>
                </xs:annotation>
                <xs:complexType>
                  <xs:attribute name="Name" type="xs:string">
                    <xs:annotation>
                      <xs:appinfo>
                        <b:fieldInfo sequence_number="1" justification="left" pad_char_type="char" pad_char=" " 
pos_length="30" pos_offset="1" />
                      </xs:appinfo>
                    </xs:annotation>
                  </xs:attribute>
                  <xs:attribute name="State" type="xs:string">
                    <xs:annotation>
                      <xs:appinfo>
                        <b:fieldInfo sequence_number="2" justification="left" pos_length="2" />
                      </xs:appinfo>
                    </xs:annotation>
                  </xs:attribute>
                  <xs:attribute name="NumSewers" type="xs:int">
                    <xs:annotation>
                      <xs:appinfo>
                        <b:fieldInfo sequence_number="3" justification="right" pos_length="8" pad_char_type="char" 
pad_char="0" />
                    ...