1. party member's identity has not been confirmed: If party member attending the meeting has doubts or disputes about someone's party member identity, he shall not sign or express his opinions at the meeting. In this case, it is necessary to further verify the person's party member identity to ensure that he meets the standards and requirements of the Party organization.

2. Different views on the resolution: If a party member has different views on the decision made at the meeting, he can choose not to sign the resolution or reserve his own views. This may be because he disagrees with the content, procedure or other aspects of the resolution.

3. Not clear about the content of the resolution: In some cases, party member may not know the specific content and significance of the resolution adopted at the meeting, so it is unable to make a clear statement. In this case, the party organization may need to explain the content and purpose of the resolution to the relevant personnel so that they can better understand and make corresponding decisions.

In a word, there may be many reasons why party member didn't sign or express his opinions at the confirmation meeting, which need to be analyzed according to the specific situation.