Suggestion Feature for tagging project:
I would like to add some tag to projects and allow filter by tag.
Why?
I have work on multiple projects in different categories and sometimes I need to focus on 1 certain thing e.g. UI Design
DoNowProject
ProjectA (development,product)
ProjectB (marketing-campaign)
DoLaterProject
ProjectC (marketing-campaign)
ProjectD (product)
I want to see all the marketing-campaign related project in 1 place
Note that we do allow filtering by tag, but it is at the note level. So you would search for #my-tag in the Search All area, and all notes with that tag would appear.
We don’t support it at the project level. Seems a bit too course for tagging. You are probably better to organise things at that level using categories, subcategories, and archiving of the projects.
The challenge is the limitation that projects can belong to only one (sub)category. See @ponlavit.lar’s ProjectA, which is tagged both development and product. Letting projects belong to multiple (sub)categories would be helpful.
One you start letting them be in two categories, things get really messy. I’ve made that mistake in other software. Simply stuff like dragging a project somewhere else becomes as difficult to understand as pure mathematics.
We decided to go the finder route with categories, and include tags at the note level. You can probably come up with a system of tagging that fits your needs. I think it is much more likely that you want to group notes from different projects, via tagging, than you do projects. You could also specialise tags to account for projects in some way. Eg. project1(green), project2(red), project1(red) etc.
I understand your point. However, I’m not using tags in Agenda much because the interface doesn’t support them so well as it does categories and projects right now. There’s no autocompletion, there’s no browser, they can only be assigned via editing the text of the note, there’s no mechanism for batch tagging, parameterization is mostly just a textual convention, there’s no nesting, tag names can’t have spaces, you can archive a project but not a tag, you can link directly to a project but not to a tag, etc.
Also, you can tag notes, but you can’t tag projects. This makes tags tedious as a means of identifying membership in areas of responsibility or focus. Projects typically belong to one or more areas. If tags are used to identify areas, and a project belongs to one or more areas, then every note in the project needs the same area tags. That’s where membership in multiple categories would be useful for projects.
I totally agree as @mike28 said. currently i do extends the name as you suggestion @drewmccormack but name search for project name is painful one since some project have product in its name but it not product tagging, and no auto completion.
We hear you, indeed tagging support is very basic at the moment, the items you mention are definitely among The features we are working on right now… Having said that, it’s not very likely we’ll add tagging of projects.
I understand and appreciate that! I just wanted to clarify why I was interested in allowing projects to belong to multiple categories or having enhancements to the tagging functions.
I may need to tweak my schema for organizing Agenda. It’s a fine tool, so I’m willing to compromise a little. 
Allowing a note or project to belong to multiple projects won’t be a likely addition, but improvements to the tag browser are definitely at the top end of the to-do list.
How about tagging / linking / associating meeting notes to catagory? It would be great to go to the catagory (e.g. Medicare) and all Medicare tagged notes are queried and collolated with timestamp?
I think NotePlan has something similar
This is what we call overviews, if you search for a tag like #medicare in the search field you can now save this search (premium feature) as an overview, which gives you this kind of view.
I did that but it pulls all the projects that has #medicare, including every other #tags.
When we meet, we cover multipe topics. So having to select a specific project/catagory is too limiting. Can we, at least, have an option to create a general note and use #tags to link to projects? I know I am not the owner of the app, but I am providing a client feedback 
I would be happy to test it for you…
Yes, it shows all projects that have #medicare, but for those projects it should only show the notes that contain the #medicare tag and hide all other notes that don’t.
I believe this thread is too old now.
I would said the categories is the project structure but be able to
add labels (or tags) would be helpful as well as i mentions.
You can make it as project metadata (no need to make it as tree like category) which user can add/remove them and be able to search (filter) on project metadata level.
We have major search improvements planned for an upcoming project. Hopefully that will address a lot of the issues people have and make tagging more useful.