documentation: Describe forward compatibility limitations

1 files changed, 6 insertions, 3 deletions

diff --git a/runtime/doc/starting.txt b/runtime/doc/starting.txt
index a3af862ad6..c75970db56 100644
--- a/runtime/doc/starting.txt
+++ b/runtime/doc/starting.txt
@@ -1024,7 +1024,8 @@ ShaDa files are forward and backward compatible.  This means that
 1. Entries which have unknown type (i.e. that hold unidentified data) are 
    ignored when reading and blindly copied when writing.
 2. Register entries with unknown register name are ignored when reading and 
-   blindly copied when writing. |registers|
+   blindly copied when writing. Limitation: only registers that use name with 
+   code in interval [1, 255] are supported. |registers|
 3. Register entries with unknown register type are ignored when reading and 
    merged as usual when writing. |getregtype()|
 4. Local and global mark entries with unknown mark names are ignored when 
@@ -1032,9 +1033,11 @@ ShaDa files are forward and backward compatible.  This means that
    entries are also blindly copied, but only if file they are attached to fits 
    in the |shada-'| limit. Unknown local mark entry's timestamp is also taken 
    into account when calculating which files exactly should fit into this 
-   limit. |mark-motions|
+   limit. Limitation: only marks that use name with code in interval [1, 255] 
+   are supported. |mark-motions|
 5. History entries with unknown history type are ignored when reading and 
-   blindly copied when writing. |history|
+   blindly copied when writing. Limitation: there can be only up to 256 
+   history types. |history|
 6. Unknown keys found in register, local mark, global mark, change, jump and 
    search pattern entries are saved internally and dumped when writing. 
    Entries created during NeoVim session never have such additions.