A. 谁知道对比文件的类别：PX、PY、PE类分别是什么意思
拷贝审查指南的原话如下：出现下列情形之一时，需要核实优先权：(1)对比文件公开了与申请的主题相同或密切相关的内容，而且对比文件的公开日在申请日和所要求的优先权日之间，即该对比文件构成ＰＸ或ＰＹ类文件；
(2)任何单位或者个人在专利局的申请所公开的内容与申请的全部主题相同，或者与部分主题相同，前者的申请日在后者的申请日和所要求的优先权日之间，而前者的公布或公告日在后者的申请日或申请日之后，即任何单位或者个人在专利局的申请构成ＰＥ类文件；
(3)任何单位或者个人在专利局的申请所公开的内容与申请的全部主题相同，或者与部分主题相同，前者所要求的优先权日在后者的申请日和所要求的优先权日之间，而前者的公布或公告日在后者的申请日或申请日之后，即任何单位或者个人在专利局的申请构成ＰＥ类文件。没有说明P/X/Y/E都是什么含义。其实，这些字母缩写来自于PCT申请检索报告中表示对比文献相关性的缩写：“A” document defining the general state of the art which is not considered to be of particular relevance
A类文献，定义为一般现有技术水平文献，没有特别相关性；“E” earlier application or patent but published on or after the international filing date
E类文献，在先文献，但公布日在国际申请日的同时或之后（需要核实是否抵触申请）；“L” document which may throw doubts on priority claim(s) or which is cited to establish the publication date of another citation or other special reason (as specified)
L类文献，可能引起对优先权要求产生怀疑的文献，或者为了确定其他引证文献的公布日期或由于其他特殊原因而引证而引证的文献；
“O” document referring to an oral disclosure, use, exhibition or other means
O类文献，指口头、使用、展览或其他方式公开的文献；“P” document published prior to the international filing date but later than the priority date claimed
P类文献，文献公开日早于申请文件国际申请日但晚于优先权日（需要核实申请文件的优先权）；“T” later document published after the international filing date or priority date and not in conflict with the application but cited to understand the principle or theory underlying the invention
T类文献，在后文件公开晚于国际申请日或优先权日，不与申请文件相冲突，但引用有助于理解发明原理；“X” document of particular relevance; the claimed invention cannot be considered novel or cannot be considered to involve an inventive step when the document is taken alone
X类文献，具有特别相关性，单独对比便可否定发明申请文件的新颖性或创造性的文献；“Y” document of particular relevance; the claimed invention cannot be considered to involve an inventive step when the document is combined with one or more other such documents, such combination being obvious to a person skilled in the art
Y类文献，具有特别相关性，与其它类似文献结合，可否定发明申请创造性的文献，这种结合对于本领域技术人员是显而易见的；“&” document member of the same patent family
&类文献，同族专利。