求德国专利代码含义

最近查了一个专利的同族专利，DE 122004000018  (I1)
DE 122004000018  (I2)
DE 69818665  (T2)
这个括号里面的代码是啥意思啊？百度了一下发现也没人说明白，希望高人赐教，在下不胜感激！
如果还有其他国家的代码含义也请一并告知，最近实在是很头疼，很多国家的专利局网站根本看不懂，比如巴西，葡萄牙文的， 英文版貌似有但不好用

T1是EP/WO公开申请的译文
T2是EP专利的译文
T3是修改后的EP专利译文
T4是EP专利或更正的EP专利译文
T5是国际申请公开的译文
I1是补充保护证书申请
I2是授权的补充保护证书

谢谢！一般从什么途径找这个代码含义啊？本人搞药物研发，对这个基本上就是靠baidu。。。

对于专利文档种类的代码世界知识产权组织制订了一个标准，即：Standard ST.16:  Identification of different kinds of patent documents (May 1997)，其PDF格式全文链接如下：http://www.wipo.int/export/sites/www/standards/en/pdf/03-16-01.pdf

德国是从2004年开始采用这一标准的。标准中对代码的释义如下：

Group 1

Use for documents resulting from a patent application and being identified as the primary or major series (excluding the utility model documents of Group 2 and the special series of patent documents as specified in Group 3, below)
A  First publication level
B  Second publication level
C  Third publication level

Group 2

Use for utility model documents having a numbering series other than the documents of Group 1
U  First publication level
Y  Second publication level
Z  Third publication level

Group 3

Use for special series of patent documents as specified below:
M  Medicament patent documents (e.g., documents previously published by FR)
P &nbsp[s:10]lant patent documents (e.g., published by US)
S  Design patent documents (e.g., published by US)

Group 4

Use for special types of patent documents or documents derived from/relating to patent applications and not covered by Groups 1 to 3, above, as specified below:
L  Documents, not covered by the letter code W, relating to patent documents and containing bibliographic information and only the text of an abstract and/or claim(s) and, where appropriate, a drawing
R  Separately published search reports
T &nbsp[s:10]ublication, for information or other purposes, of the translation of the whole or part of a patent document already published by another office or organization
W  Documents relating to utility model documents falling in Group 2 and containing bibliographic information and only the text of an abstract and/or claim(s) and, where appropriate, a drawing

Group 5

Use for series of patent documents not covered by Groups 1 to 4, above
E  First publication level
F  Second publication level
G  Third publication level

Group 6

Use for series of patent documents or documents derived from/relating to patent applications and not covered by Groups 1 to 5, above, according to the special requirements of each industrial property office
H
I

Group 7

Other (see paragraph 2, above)
N  Non-patent literature documents
X  Documents restricted to the internal use of industrial property offices.