See https://developer.yahoo.com/fantasysports/guide/ for details

transaction_resource_example.xml

<?xml version="1.0" encoding="UTF-8"?>
<fantasy_content xmlns:yahoo="http://www.yahooapis.com/v1/base.rng" xmlns="http://fantasysports.yahooapis.com/fantasy/v2/base.rng" xml:lang="en-US" yahoo:uri="http://fantasysports.yahooapis.com/fantasy/v2/transaction/257.l.193.tr.2" time="51.784038543701ms" copyright="Data provided by Yahoo! and STATS, LLC">
  <transaction>
    <transaction_key>257.l.193.tr.2</transaction_key>
    <transaction_id>2</transaction_id>
    <type>add/drop</type>
    <status>successful</status>
    <timestamp>1310694660</timestamp>
    <players count="2">
      <player>
        <player_key>257.p.7847</player_key>
        <player_id>7847</player_id>
        <name>
          <full>Owen Daniels</full>
          <first>Owen</first>
          <last>Daniels</last>
          <ascii_first>Owen</ascii_first>
          <ascii_last>Daniels</ascii_last>
        </name>
        <transaction_data>
          <type>add</type>
          <source_type>freeagents</source_type>
          <destination_type>team</destination_type>
          <destination_team_key>257.l.193.t.1</destination_team_key>
        </transaction_data>
      </player>
      <player>
        <player_key>257.p.6390</player_key>
        <player_id>6390</player_id>
        <name>
          <full>Anquan Boldin</full>
          <first>Anquan</first>
          <last>Boldin</last>
          <ascii_first>Anquan</ascii_first>
          <ascii_last>Boldin</ascii_last>
        </name>
        <transaction_data>
          <type>drop</type>
          <source_type>team</source_type>
          <source_team_key>257.l.193.t.1</source_team_key>
          <destination_type>waivers</destination_type>
        </transaction_data>
      </player>
    </players>
  </transaction>
</fantasy_content>