diff --git a/lua/fzf-lua/core.lua b/lua/fzf-lua/core.lua
index 3c0c854..f82603c 100644
--- a/lua/fzf-lua/core.lua
+++ b/lua/fzf-lua/core.lua
@@ -125,6 +125,19 @@ M.fzf = function(opts, contents)
       --     calls without displaying the native fzf previewer split
       opts.fzf_opts['--preview-window'] = previewer:preview_window(opts.preview_window)
     end
+    -- provides preview offset when using native previewers
+    -- (bat/cat/etc) with providers that supply line numbers
+    -- (grep/quickfix/LSP)
+    if type(previewer.fzf_delimiter) == 'function' then
+      opts.fzf_opts["--delimiter"] = previewer:fzf_delimiter()
+    end
+    if type(previewer.preview_offset) == 'function' then
+      opts.preview_offset = previewer:preview_offset()
+    end
+  elseif not opts.preview and not opts.fzf_opts['--preview'] then
+    -- no preview available, override incase $FZF_DEFAULT_OPTS
+    -- contains a preview which will most likely fail
+    opts.fzf_opts['--preview-window'] = 'hidden:right:0'
   end
 
   if opts.fn_pre_fzf then
@@ -405,21 +418,6 @@ end
 
 M.set_fzf_line_args = function(opts)
   opts._line_placeholder = 2
-  -- set delimiter to ':'
-  -- entry format is 'file:line:col: text'
-  opts.fzf_opts["--delimiter"] = vim.fn.shellescape('[:]')
-  --[[
-    #
-    #   Explanation of the fzf preview offset options:
-    #
-    #   ~3    Top 3 lines as the fixed header
-    #   +{2}  Base scroll offset extracted from the second field
-    #   +3    Extra offset to compensate for the 3-line header
-    #   /2    Put in the middle of the preview area
-    #
-    '--preview-window '~3:+{2}+3/2''
-  ]]
-  opts.preview_offset = string.format("+{%d}-/2", opts._line_placeholder)
   return opts
 end
 
diff --git a/lua/fzf-lua/previewer/fzf.lua b/lua/fzf-lua/previewer/fzf.lua
index f640954..c820b78 100644
--- a/lua/fzf-lua/previewer/fzf.lua
+++ b/lua/fzf-lua/previewer/fzf.lua
@@ -22,6 +22,40 @@ function Previewer.base:preview_window(_)
   return nil
 end
 
+function Previewer.base:preview_offset()
+  --[[
+    #
+    #   Explanation of the fzf preview offset options:
+    #
+    #   ~3    Top 3 lines as the fixed header
+    #   +{2}  Base scroll offset extracted from the second field
+    #   +3    Extra offset to compensate for the 3-line header
+    #   /2    Put in the middle of the preview area
+    #
+    '--preview-window '~3:+{2}+3/2''
+  ]]
+  if self.opts._line_placeholder then
+    return ("+{%d}-/2"):format(self.opts._line_placeholder)
+  end
+end
+
+function Previewer.base:fzf_delimiter()
+  if not self.opts._line_placeholder then return end
+  -- set delimiter to ':'
+  -- entry format is 'file:line:col: text'
+  local delim = self.opts.fzf_opts and self.opts.fzf_opts["--delimiter"]
+  if not delim then
+    delim = '[:]'
+  elseif not delim:match(":") then
+    if delim:match("%[.*%]")then
+      delim = '[:' .. delim:match("%[(.*%])")
+    else
+      delim = '[:' .. delim .. ']'
+    end
+  end
+  return delim
+end
+
 -- Generic shell command previewer
 Previewer.cmd = Previewer.base:extend()
 
diff --git a/lua/fzf-lua/providers/nvim.lua b/lua/fzf-lua/providers/nvim.lua
index 57e29ff..43575a4 100644
--- a/lua/fzf-lua/providers/nvim.lua
+++ b/lua/fzf-lua/providers/nvim.lua
@@ -189,7 +189,7 @@ M.marks = function(opts)
   local marks = vim.fn.execute("marks")
   marks = vim.split(marks, "\n")
 
-  local prev_act = shell.action(function (args, fzf_lines, _)
+  --[[ local prev_act = shell.action(function (args, fzf_lines, _)
     local mark = args[1]:match("[^ ]+")
     local bufnr, lnum, _, _ = unpack(vim.fn.getpos("'"..mark))
     if vim.api.nvim_buf_is_loaded(bufnr) then
@@ -201,7 +201,7 @@ M.marks = function(opts)
       end
       return "UNLOADED: " .. name
     end
-  end)
+  end) ]]
 
   local entries = {}
   for i = #marks, 3, -1 do
@@ -215,7 +215,7 @@ M.marks = function(opts)
 
   table.sort(entries, function(a, b) return a<b end)
 
-  opts.fzf_opts['--preview'] = prev_act
+  -- opts.fzf_opts['--preview'] = prev_act
   opts.fzf_opts['--no-multi'] = ''
 
   core.fzf_wrap(opts, entries, function(selected)
diff --git a/lua/fzf-lua/providers/tags.lua b/lua/fzf-lua/providers/tags.lua
index abf04db..6b9796f 100644
--- a/lua/fzf-lua/providers/tags.lua
+++ b/lua/fzf-lua/providers/tags.lua
@@ -65,7 +65,7 @@ local fzf_tags = function(opts)
       if not grep_cmd then grep_cmd = get_grep_cmd() end
       local line = 1
       local filepath = path.join({cwd, t.file})
-      local pattern = utils.rg_escape(t.text:match("/(.*)/"))
+      local pattern = utils.rg_escape(t.text:match("/^?(.*)/"))
       if not pattern or not filepath then return line end
       -- ctags uses '$' at the end of short patterns
       -- 'rg|grep' does not match these properly when
@@ -123,7 +123,9 @@ local fzf_tags = function(opts)
                   }, cb, co,
                   -- unless we're using native previewer
                   -- do not need to extract the line number
-                  type(opts.previewer) == 'table')
+                  not opts.previewer
+                  or opts.previewer == 'builtin'
+                  or type(opts.previewer) == 'table')
               end)
               -- pause here until we call coroutine.resume()
               coroutine.yield()